Truth has a variety of meanings, such as the state of being in accord with fact
A fact is something that has really occurred or is actually the case. The usual test for a statement of fact is verifiability, that is whether it can be shown to correspond to experience. Standard reference works are often used to check facts...

 or reality
In philosophy, reality is the state of things as they actually exist, rather than as they may appear or might be imagined. In a wider definition, reality includes everything that is and has been, whether or not it is observable or comprehensible...

. It can also mean having fidelity to an original or to a standard or ideal. In a common usage, it also means constancy or sincerity in action or character. The direct opposite
Principle of bivalence
In logic, the semantic principle of bivalence states that every declarative sentence expressing a proposition has exactly one truth value, either true or false...

 of truth is falsehood
False or falsehood may refer to:*False *Lie or falsehood, a type of deception in the form of an untruthful statement*Falsity or falsehood, in law, deceitfulness by one party that results in damage to another...

, which can correspondingly take logical, factual or ethical meanings.

However, language and words are essentially "tools" by which humans convey information
Information in its most restricted technical sense is a message or collection of messages that consists of an ordered sequence of symbols, or it is the meaning that can be interpreted from such a message or collection of messages. Information can be recorded or transmitted. It can be recorded as...

 to one another.

The impossible often has a kind of integrity to it which the merely improbable lacks.

Douglas Adams in The Long Dark Tea-Time of the Soul|The Long Dark Tea-Time of the Soul; spoken by the character Dirk Gently|Dirk Gently

To say of what is, that it is, or of what is not, that it is not, is true.

Aristotle in Metaphysics (Book 4)

Not being known doesn't stop the truth from being true.

Richard Bach, in There's No Such Place As Far Away (1978)

You must be ever vigilant to discover the unifying Truth behind all the scintillating variety.

Sathya Sai Baba Thought for the day 5th October 2008

What is truth? said jesting Pilate, but would not stay for an answer.

Francis Bacon, Essays 1: Of truth

No pleasure is comparable to standing upon the vantage-ground of truth.

Francis Bacon, reported in Josiah Hotchkiss Gilbert, Dictionary of Burning Words of Brilliant Writers (1895), p. 603.

Yes, there is a Divinity, one from which we must never turn aside for the guidance of our huge inward life and of the share we have as well in the life of all men. It is called the truth.

Henri Barbusse in Under_Fire_(novel)|Under Fire (1916)

Truth is the cry of all, but the game of the few.

George Berkeley, in Siris, par. 368

The world is made up, for the most part, of fools and knaves, both irreconcilable foes to truth.

George Villiers, 2nd Duke of Buckingham, in "Letter to Mr. Clifford, on his Human Reason"; also in The Works of His Grace, George Villiers, the Duke of Buckingham (London: T. Evans, 1770) vol. 2, p. 105.