postulate vs cost

postulate and cost both are nouns.

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

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

Other hyponyms of postulate include claim, exact, take, govern, draw, cry for, cry out for, compel.

postulate (noun)	cost (noun)
(logic) a proposition that is accepted as true in order to provide a basis for logical reasoning	the property of having material worth (often indicated by the amount of money something would bring if sold)
	value measured by what must be given or done or undergone to obtain something
	the total spent for goods or services including money and time and labor

postulate (verb)	cost (verb)
take as a given; assume as a postulate or axiom	be priced at
maintain or assert	require to lose, suffer, or sacrifice
require as useful, just, or proper