A
definition is a statement of the meaning of a term (a
word,
phrase, or other set of
symbols). Definitions can be classified into two large categories:
intensional definitions (which try to give the sense of a term), and
extensional definitions (which try to list the objects that a term describes) ....
In modern usage, a definition is something, typically expressed in words, that attaches a meaning to a word or group of words. The word or group of words that is to be defined is called the
definiendum, and the word, group of words, or action that defines it is called the
definiens. For example, in the definition
"An elephant is a large gray animal native to Asia and Africa", the word "elephant" is the
definiendum, and everything after the word "is" is the
definiens.