definitive

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Precisely defined or explicit.
2. adj. Supplying or being a final settlement or decision; conclusive. See Synonyms at decisive.
3. adj. Authoritative and complete: a definitive biography. See Usage Note at definite.
4. adj. Biology Fully formed or developed, as an organ or structure.
5. n. Grammar A word that defines or limits, such as the definite article or a demonstrative pronoun.

Century Dictionary and Cyclopedia

1. Limiting the extent; determinate; positive; express: as, a definitive term.
2. Ending; determining; final; conclusive: opposed to conditional, provisional, or interlocutory.
3. Specifically— In biology, completely formed; fixed and finished: opposed to primitive or formative: as, the definitive aorta; a definitive anus.
4. In logic, applied to a judgment which is accompanied by a full assent of the mind.
5. In metaphysics, having position without occupying space.
6. n. In grammar, a defining or limiting word, as an article, a demonstrative, or the like.
7. To make definite.

Wiktionary

1. adj. explicitly defined
2. adj. conclusive or decisive
3. adj. definite, authoritative and complete
4. adj. philately general, not issued for commemorative purposes
5. n. grammar a word, such as a definite article or demonstrative pronoun, that defines or limits something
6. n. philately an ordinary postage stamp that is part of a series of all denominations or is reprinted as needed to meet demand

GNU Webster's 1913

1. adj. Determinate; positive; final; conclusive; unconditional; express.
2. adj. Limiting; determining.
3. adj. obsolete Determined; resolved.
4. n. (Gram.) A word used to define or limit the extent of the signification of a common noun, such as the definite article, and some pronouns.

WordNet 3.0

1. adj. clearly defined or formulated
2. adj. of recognized authority or excellence
3. adj. supplying or being a final or conclusive settlement