necessitate vs postulate

necessitate is not a noun while postulate is a noun.

Word	Noun	Adjective	Verb	Adverb
necessitate	No	No	Yes	No
postulate	Yes	No	Yes	No

As verbs, necessitate and postulate are synonyms defined as:

Other synonyms of necessitate include ask, call for, demand, involve, need, require, take.

necessitate (noun)	postulate (noun)
	(logic) a proposition that is accepted as true in order to provide a basis for logical reasoning

necessitate (verb)	postulate (verb)
require as useful, just, or proper	take as a given; assume as a postulate or axiom
cause to be a concomitant	maintain or assert
	require as useful, just, or proper