decisive vs determinant

decisive is not a noun while determinant is a noun.

Word	Noun	Adjective	Verb	Adverb
decisive	No	Yes	No	No
determinant	Yes	Yes	No	No

decisive (noun)	determinant (noun)
	a determining or causal element or factor
	a square matrix used to solve simultaneous equations
	the site on the surface of an antigen molecule to which an antibody attaches itself

decisive (adjective)	determinant (adjective)
determining or having the power to determine an outcome	having the power or quality of deciding
characterized by decision and firmness
forming or having the nature of a turning point or crisis
unmistakable