Definitive

Part of speech: noun (n.)

A word used to define or limit the extent of the signification of a common noun, such as the definite article, and some pronouns.

Part of speech: adjective (a.)

1. Determinate; positive; final; conclusive; unconditional; express. A strict and definitive truth. Sir T. Browne. Some definitive . . . scheme of reconciliation. Prescott.

2. Limiting; determining; as, a definitive word.

3. Determined; resolved. [Obs.] Shak.