Noun: 1.

a. A statement of the meaning of a word, phrase, or term, as in a dictionary entry.

b. A statement or description of the fundamental character or scope of something: "[The panel] calls for a clearer definition of the status of people captured in American military operations" (Economist).

2. The act or process of stating a precise meaning or significance; formulation of a meaning: The definition of terms is essential to any successful scholarly study.

3. The state of being clearly outlined: "With the drizzle, the trees in the little clearing had lost definition" (Anthony Hyde).

4. The level of detail in a recording, production, or digital encoding of an image or sound.