M The letter M is the thirteenth letter in the Latin alphabet. Its name in English language is em .
	M-theory In physics, M-theory is put forward as the master theory that unifies the five string theory. Drawing on the work from a number of string theorists , Edward Witten of the Institute for Advanced Study proposed the existence of this physical model at a conference at University of Southern California in 1995, explaining a number of previously observed dualities and sparking a flurry of new research in string theory, called the second superstring revolution.
	Maar A Maar is a broad, low relief crater that is caused by a phreatic eruption or explosion caused by groundwater contact with hot lava or magma. The maar typically fills with water to form a relatively shallow crater lake. Maars are shallow, flat-floored craters that scientists interpret have formed above diatremes as a result of a violent expansion of magmatic gas or steam; deep erosion of a maar presumably would expose a diatreme.
	Macabre Macabre is a term applied to a type of artistic or literature works, characterized by a grim or ghastly atmosphere. In these works, there is an emphasis on the details and symbols of death. Macabre themes are often preoccupations in the Goth subculture. Themes are usually deliberate.
	Macadamia Macadamia is a genus of eight species of flowering plants in the family Proteaceae, with a disjunct distribution native to eastern Australia and Indonesia. They are small to large evergreen trees growing to 6-40 m tall. The leaf are arranged in whorls of three to six, lanceolate to obovate or elliptical in shape, 6-30 cm long and 2-13 cm broad, with an entire or spiny-serrated margin.
	Macaque The macaques are Old World monkeys of the subfamily Cercopithecinae. Aside from humans, the macaques are the most widespread primate genus, ranging from northern Africa to Japan. Twenty-two macaque species are currently recognised, and they include some of the monkeys best known to non-zoologists, such as the Rhesus Macaque, Macaca mulatta, and the Barbary Macaque, M.
	Macaroni Macaroni is typically machine-made dry commercial pasta, used in contrast to fresh pasta made at home or in small local businesses. Macaroni technically must not contain eggs. Although usually commercially made, some more advanced home machines do allow for the fresh creation of macaroni pasta noodles.
	Macaroni and cheese Macaroni and cheese is a common dish whose main ingredients are cooked macaroni and a cheese sauce. Cheddar cheese is the traditional choice. However, other cheese may be used. Packaged versions are available, consisting of boxed pasta and a cheese powder, to which is added butter and milk.
	Macaroon Macaroons are a cookie or confection, or a cross between the two, depending on where they are made. The macaroon is a close cousin to the meringue. The original macaroon is the cookie version, made with powdered almonds, which originated in Italy. The English word macaroon comes from the French macaron, from the Italian maccarone meaning "dumpling" - because almond macaroon paste is the same colour as macaroni pasta.
	Macau The Macau Special Administrative Region of the People's Republic of China , commonly known as Macau or Macao is a small territory on the southern coast of China. Administered by Portugal until 1999, it was the oldest European colony in China, dating back to the 16th century.
	Macaw Macaws are large colorful the Americas parrots, classified into six of the many Psittacidae genus: Ara, Anodorhynchus, Cyanopsitta, Propyrrhura, Orthopsittaca, and Diopsittaca. They are the largest birds in the parrot family in length and wingspan, though the flightless Kakapo is heavier.
	Macbeth 'The Tragedy of Macbeth is among the most popular of William Shakespeare's Shakespeare's plays, as well as his shortest Shakespearean tragedy. It is frequently performed at professional and community theatres around the world. The play is seen as an Archetype tale of the dangers of the lust for power and betrayal of friends.
	Mace An advance on the club , a mace is a strong, heavy wooden, metal-reinforced, or metal shaft, with a head made of stone, copper, bronze, iron or steel. The head is normally about the same or slightly thicker than the diameter of the shaft, shaped with flanges, or knobs to allow greater penetration of armour.
	Macedon Macedon or Macedonia was the name of an ancient kingdom in the northern-most part of ancient Greece, bordering the kingdom of Epirus on the west and the region of Thrace to the east. For a brief period it became the most powerful state in the ancient Near East after Alexander the Great conquered most of the known world, inaugurating the Hellenistic civilization of Greek history.
	Mach number Mach number is defined as a ratio of the speed of an object or flow relative to the speed of sound in the medium through which it is travelling: whereIn other words, Mach is the number of times the speed of sound something goes The Mach number is named after Austria physicist and philosopher Ernst Mach.
	Machete The machete is a Cleaver -like tool that looks like a very large knife. The blade is typically 50–60 centimeter long, usually with a thin blade under 3mm thick. In the English language, an equivalent term is matchet . The machete is normally used to cut through thick vegetation such as sugar cane or jungle undergrowth but it can also be used as an offensive weapon.
	Machicolation A machicolation is a floor opening between the supporting corbels of a battlement, through which Rocks could be dropped on attackers at the base of a defensive wall. A machicolated battlement projects outwards from the supporting wall in order to facilitate this. A hoarding is a similar structure made of wood, usually temporarily constructed in the event of a seige.
	Machine A machine is any mechanics or organic compound device that transmits or modifies energy to perform or assist in the performance of tasks. It normally requires some energy source and accomplishes some sort of mechanical work. People have used mechanisms and machines to amplify their abilities since before written records were available.
	Machine gun A machine gun is a Automatic firearm mounted or portable firearm, usually designed to fire List of rifle cartridgess in quick succession from an Belt or large-capacity Magazine , typically at a rate of several hundred bullets per minute.
	Machine pistol A machine pistol combines several properties of the semi-automatic self-loading pistol and the submachine gun. Machine pistols are magazine-fed and self-cocking. These weapons are capable of Automatic_firearm or burst fire, and being the size of a pistol are able to be held comfortably in one hand.
	Machine translation Machine translation, sometimes referred to by the acronym MT, is a sub-field of computational linguistics that investigates the use of computer software to translation text or speech from one natural language to another. At its basic level, MT performs simple substitution of atomic words in one natural language for words in another.
	Machu Picchu Machu Picchu is a well-preserved pre-Columbian Inca Empire ruin located on a high mountain ridge. Elevation measurements vary depending on whether the data refers to the ruin or the extremity of the mountain; Machu Picchu tourism information reports the elevation as 2,350 m .
	Macintosh The Macintosh, or Mac, is a line of personal computers designed, developed, manufactured, and marketed by Apple Computer. Named after the McIntosh, the Macintosh 128K was released on January 24, 1984. It was the first commercially successful personal computer to use a graphical user interface and Mouse instead of the then-standard command line interface.
	Mack Sennett Mack Sennett was an innovator of slapstick comedy in film. During his lifetime he was known as the King of Comedy.
	Mackenzie River The Mackenzie River originates in Great Slave Lake, in the Northwest Territories, and flows north into the Arctic Ocean. It is the longest river in Canada at 1,738 km and, together with its headstreams the Peace River and the Finlay River, the second longest river in North America at 4,241 km in length; only the Mississippi River-Missouri River is longer.
	Mackinac Bridge The Mackinac Bridge , is a suspension bridge spanning the Straits of Mackinac to connect the non-contiguous Upper Peninsula of Michigan and Lower Peninsula of Michigan peninsulas of the U.S. state of Michigan. Envisioned since the 1880s, the bridge was completed only after many decades of struggles to begin construction.
	Mackintosh A Mackintosh is a form of waterproof raincoat, first sold in 1824, made out of rubberized fabric. The Mackintosh is named after its Scotland inventor Charles Macintosh: note the added letter 'k' in the name of the garment. Although the Mackintosh style of coat has become generic, a genuine Mackintosh coat should be made from rubberised or rubber laminated material.
	Mâcon Mcon is a commune in France of France, prfecture of the Sane-et-Loire dpartement in France, in the Bourgogne rgion in France.
	Macramé Macram or macrame is a form of textile-making using knotting rather than weaving or knitting. Its primary knots are the square knot and forms of hitching. It has been used by sailors, especially in elaborate or ornamental knotting forms to decorate anything from knife handles to bottles to parts of ships.
	Macromolecule A macromolecule is a large molecule with a large molecular mass, but generally the use of the term is restricted to polymers and molecules which structurally include polymers. Many examples come from biology and in particular biochemistry. In case of "biomacromolecules" or biopolymers, there are proteins, polysaccharide, nucleic acids, and lipids.
	Macrophage Macrophages are cells within the tissues that originate from specific white blood cells called monocytes. Monocytes and macrophages are phagocytes, acting in both nonspecific defence
	Macropus Macropus is a marsupial genus that belongs to the family Macropod, it has 14 species which are further divided into 3 subgenera. The genus includes all terrestrial kangaroos, wallaroos and several species of wallaby. * Genus Macropus ** Subgenus Notamacropus
	Macrozamia Macrozamia is a genus of 38-40 species of cycads, in the family Zamiaceae, endemic to Australia. The majority of the species occur in eastern Australia in southeast Queensland and New South Wales, with one species in the Macdonnell Ranges of Northern Territory and three in southern Western Australia.
	Macrozamia communis Macrozamia communis is an Australian cycad found on the east coast of New South Wales. The common name for the species is burrawang, a word derived from the Daruk Australian Aboriginal languages; this name is also often applied to other species of Macrozamia.
	Macula "Macula" can also mean a "stain on the soul" in Catholicism; see mortal sin. "Macula" is also a term used in planetary geology, see Macula, and aerial archaeology see Macula. The macula or macula lutea is an oval yellow spot near the center of the retina of the human eye.
	Macular degeneration Macular degeneration is a medical condition in which the light sensing cells in the macula malfunction and, over time, cease to work. According to the American Academy of Ophthalmology, it is the leading cause of central vision loss in the United States today for those over the age of fifty years.
	Macule The macule is the simplest dermatological lesion. It is flat and can only be seen and not felt. The macule is noted by a change in color of the skin. It may be brown, blue, red or exhibit a lesser pigment or an absence of pigment. The color of the lesion is one way in which a diagnosis may be focused.
	Madagascar Madagascar, , is an island nation in the Indian Ocean, off the eastern coast of Africa, close to Mozambique. The main island, also called Madagascar, is the List of islands by size. It is home to five percent of the world's plant and animal species, more than 80 percent of them endemic to Madagascar.
	Madame Tussauds Madame Tussauds is a wax museum in London, with branches in Amsterdam, Hong Kong, Las Vegas, Nevada, New York City, Shanghai, and Hollywood. It was set up by wax sculptor Marie Tussaud. Madame Tussaud, born Marie Tussaud in Strasbourg, worked as a housekeeper for Dr.
	Madder Madder is the common name of the plant genus Rubia, the biological type of the madder family Rubiaceae. The genus contains about 60 species of perennial scrambling or climbing herbs and sub-shrubs native to the Old World, Africa, temperate Asia and America.
	Madeira Madeira is a Portugal archipelago in the north Atlantic Ocean that lies between and . It is one of the Autonomous regions of Portugal, with Madeira and Porto Santo being the only inhabited islands. Madeira, known originally to the Romans as the Purple Islands, was rediscovered, possibly accidentally, by Portugal sailors and settled by Portugal in 1418.
	Madman Madman is a comic book series set in one of the many Parallel universe existing in the Multiverse. Mike Allred is the creator of the Madman comic book and all its characters. Madman's world is particularly strange. It is a world where mutants, extraterrestrials and freaks run rampant.
	Madonna lily The Madonna Lily is a plant in the genus Lilium, a "true lily". It is native to the Balkans and West Asia. It forms bulbs at ground level, and unlike other lilies, has a basal rosette of leaves through the winter, which die back in summer. A leafy flower stem, typically up to 1.2 m high, sometimes up to 2 m high, emerges in late spring and bears fragrant flowers in summer.
	Madrasah The word madrasah means school or "learning center". It is variably transliterated as madrasah, madrash, medresa, or madressa.
	Madrid Madrid is the capital of Spain. Madrid is the largest city in Spain, as well as in the Madrid and the Madrid of the same name. It is located on the river Manzanares in the center of the country, between the provinces of Castilla y Leon and Castilla la Mancha.
	Mae West Mae West was an United States actor, playwright, screenwriter, and sex symbol. Famous for her bawdy double entendres, West made a name for herself in vaudeville and on the legitimate theatre in New York City before moving to Hollywood, Los Angeles, California to conquer and make her unforgettable place among the great performers of the film industry.
	Maelstrom A maelstrom is a powerful whirlpool; a large, swirling body of water. The word is a compound of the Dutch language words malen and stroom. The original Maelstrom is the Moskstraumen, a powerful tidal current in the Lofoten Islands off the Norway.
	Maenad In Greek mythology, Maenads were female worshippers of Dionysus, the Greek mythology god of mystery religion, wine and intoxication, and the Ancient Rome god Bacchus. The word literally translates as "raving ones". They were known as wild, insane women who could not be reasoned with.
	Mafia The Mafia, also referred to in Italian language as Cosa Nostra , is a secret society formed in the mid-19th century in Sicily. An offshoot emerged on the East Coast of the United States of the United States during the late 19th century following waves of Italian immigration to that country.
	Magazine A magazine is a periodical publication containing a variety of articles, generally financed by advertising and/or purchase by readers. Magazines are typically published weekly, biweekly, monthly, bimonthly or quarterly, with a periodical cover date that is in advance of the date it is actually published.
	Magdalena River The Magdalena River is the principal river of Colombia, running about 1,540 kilometres from South to North through the western half of the country. It takes its name from the biblical figure, Mary Magdalene. It is navigable through much of its lower reaches. Its headwaters are in the South of the country, where the Andes subranges Cordillera Central, Colombia and Cordillera Oriental, Colombia separate, in Huila Department.
	Magellanic Clouds |- | |} The two Magellanic Clouds are irregular galaxy dwarf galaxy Galaxy classification orbiting our Milky Way galaxy, and thus are members of our Local Group of galaxies.
	Magenta Magenta is a color made up of equal parts of red and blue light. This would be the precise definition of the color. It is a pure chroma on the color wheel between violet and red. Magenta, in the Munsell Colour System, lies between on the Color wheel between purple and red, and therefore it is a pure chroma.
	Maggot A maggot is the larval stage of the fly life cycle, famous for eating decomposing flesh. Sometimes "maggot" is used to refer to the larval stage of any insect.
	Maghreb The Maghreb
	Magi The Magi was a tribe from ancient Medes, who - prior to the absorption of the Medes into the Persian Empire in 550 BC - were responsible for religious and funerary practices. Later they accepted the Zoroastrianism religion, however, not without changing the original message of its founder, Zoroaster, to what is today known as "Zurvanism", which would become the predominant form of Zoroastrianism during the Sassanid Empire.
	Magic square In recreational mathematics, a magic square of order n is an arrangement of n numbers, usually distinct integers, in a square , such that the n numbers in all rows, all columns, and both diagonals sum to the same constant. A normal magic square contains the integers from 1 to n.
	Magicicada Magicicada is the genus of the 13- and 17- year periodical cicadas of eastern North America. These insects display a unique combination of long life cycles, periodicity, and mass emergences. They sometimes go by the common name "seventeen-year locust", but they are not locusts at all; locusts belong to the order Orthoptera.
	Maginot Line The Maginot Line was a line of concrete fortifications, tank obstacles, machine gun posts and other defenses which France constructed along its borders with Germany and with Italy in the wake of World War I. Generally the term describes either the entire system or just the defences facing Germany while the Alpine Line is used for the Franco-Italian defences.
	Magna Carta Magna Carta , also called Magna Carta Libertatum , is an Kingdom of England charter originally issued in 1215. Magna Carta was the most significant early influence on the long historical process that led to the rule of constitutional law today. Magna Carta was originally created because of disagreements between Pope Innocent III, John of England and his English barons about the rights of the British monarchy.
	Magnate Magnate, from the Late Latin magnas, a great man, itself from Latin magnus 'great', designates a noble or other man in a high social position, by birth, wealth or other qualities. The term was specifically applied to the members of the Upper House in the Apostolic kingdom of Hungary, the Forendihz or House of Magnates.
	Magnesite Magnesite is magnesium carbonate, MgCO3. Iron substitutes for Mg with a complete solution series with siderite, FeCO3. Calcium, manganese, cobalt, and nickel may also occur in small amounts. Dolomite,CO3, is almost indistinguishable from magnesite.
	Magnesium Magnesium is the chemical element in the periodic table that has the symbol Mg and atomic number 12 and an atomic mass of 24.31. Magnesium is the eighth most abundant element and constitutes about 2% of the Earth's Crust by weight, and it is the third most plentiful element dissolved in seawater.
	Magnesium carbonate Magnesium carbonate, MgCO3, is a white solid that occurs in nature as a mineral. Several hydrated and Base forms of magnesium carbonate also exist as minerals. In addition, MgCO3 has a variety of applications.
	Magnesium nitride Magnesium nitride, Mg3N2, is an inorganic compound of magnesium and nitrogen. At room temperature and pressure it is a greenish yellow powder. It reacts with water to produce ammonia gas, as do many metal nitrides. Mg3N2 + 6H2O ? 3Mg(OH)2 + 2NH3
	Magnesium oxide Magnesium oxide is a white solid mineral that occurs naturally as periclase and is a source of magnesium. See also oxide. It has an empirical formula of . It is formed by an ionic bond between one magnesium and one oxygen atom.
	Magnesium sulfate align="right" border="1" cellspacing="0" cellpadding="3" style="margin: 0 0 0 0.5em; background: #FFFFFF; border-collapse: collapse; border-color: #C0C090;" ! | Magnesium sulfate |- | align="center" colspan="2" | |- ! | General |- | IUPAC nomenclature | Magnesium sulfate heptahydrate
	Magnet A magnet is an object that has a magnetic field. It can be in the form of a permanent magnet or an electromagnet. Permanent magnets do not rely upon outside influences to generate their field. They occur naturally in some Rock s, but can also be manufactured. Electromagnets rely upon electric current to generate a magnetic field - when the current increases, so does the field.
	Magnetic core A magnetic core is the core of an electromagnet or inductor. The properties of an electromagnet or inductor will be influenced by the core with the most important factors being: * the geometry of the magnetic core. * the amount of air gap in the magnetic circuit. * the magnetic core material.
	Magnetic field In physics, a magnetic field is that part of the electromagnetic field that exists when there is a changing electric field. A changing electric field can be caused by the movement of an electrically charged object, as in an electric current; or a combination of the orbit of an electron around an atom and the spin of electrons themselves, as in a permanent magnet.