What does "definitive" mean?

Additional senses

1. 2.Determined; resolved. [Obs.] Shak.
2. 3.A word used to define or limit the extent of the signification of a common noun, such as the definite article, and some pronouns. Note: Definitives . . . are commonly called by grammarians articles. . . . They are of two kinds, either those properly and strictly so called, or else pronominal articles, such as this, that, any, other, some, all, no, none, etc. Harris (Hermes).