A statement of the meaning of a term. The term to be defined is the definiendum. The term may have different senses and multiple meanings. For each meaning, definiens is a
cluster of words that defines that term.
A definition will vary in aspects like
precision or popularity. There are also different types of definitions with different purposes and focuses (e.g. intensional, extensional, descriptive, stipulative, and so on).
A chief difficulty in the management of definitions is the
necessity of using other terms that are already understood or whose definitions are easily obtainable or demonstrable (e.g.
a need, sometimes, for ostensive definitions).
A dictionary definition typically contains additional details about a word, such as an etymology and the language or languages of its origin, or
obsolete meanings.