(Reasons for defining terms) or why are definitions necessary in logic? These are five reasons.

1. To increase vocabulary: to explain the meaning of a term is to give its definition. A definition is required to understand what is being said.
2. To eliminate ambiguity: when a word has more than two meanings, it is necessary to know which one is exactly intended. This is to resolve verbal disputes.
3. To clarify meaning: when a vague term is used or to reduce vagueness.
4. To explain theoretically
5. To influence attitude: they may be used to stir emotions of one’s readers or hearers in a certain definite way.