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