suppose vs postulate

suppose is not a noun while postulate is a noun.

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

As verbs, postulate is a hyponym of suppose; that is, postulate is a word with a more specific, narrower meaning than suppose:

Other hyponyms of suppose include posit, premise, premiss.

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

suppose (verb)	postulate (verb)
expect, believe, or suppose	take as a given; assume as a postulate or axiom
to believe especially on uncertain or tentative grounds	maintain or assert
require as a necessary antecedent or precondition	require as useful, just, or proper
take for granted or as a given; suppose beforehand
express a supposition