A precising definition
is a definition
A definition is a passage that explains the meaning of a term , or a type of thing. The term to be defined is the definiendum. A term may have many different senses or meanings...
that extends the lexical definition
The lexical definition of a term, also known as the dictionary definition, is the meaning of the term in common usage. As its other name implies, this is the sort of definition one is likely to find in the dictionary...
of a term for a specific purpose by including additional criteria that narrow down the set of things meeting the definition.
For example, a dictionary may define the term "student" as "1. anyone attending an educational institution of any type, or 2. anyone who studies something." However, a movie theater may propose a precising definition
for the word "student" of "any person under the age of 18 enrolled in a local school" in order to determine who is eligible to receive discounted tickets.
Precising definitions are generally used in contexts where vagueness
The term vagueness denotes a property of concepts . A concept is vague:* if the concept's extension is unclear;* if there are objects which one cannot say with certainty whether belong to a group of objects which are identified with this concept or which exhibit characteristics that have this...
is unacceptable; many legal
Law is a system of rules and guidelines which are enforced through social institutions to govern behavior, wherever possible. It shapes politics, economics and society in numerous ways and serves as a social mediator of relations between people. Contract law regulates everything from buying a bus...
definitions are precising definitions, as are company policies. This type of definition is useful in preventing disputes that arise from the involved parties using different definitions of the term in question.
A precising definition is intended to make a vague word more precise so that the word's meaning is not left to the interpretation of the reader or listener. Here is an example:
From a class syllabus:
"Class participation" means attending class, listening attentively, answering and asking questions, and participating in class discussions.
This is similar to a stipulative definition
A stipulative definition is a type of definition in which a new or currently-existing term is given a specific meaning for the purposes of argument or discussion in a given context. When the term already exists, this definition may, but does not necessarily, contradict the dictionary definition of...
, but differs in that a stipulative definition may contradict the lexical definition, while a precising definition does not.