suppose vs guess

suppose is not a noun while guess is a noun.

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

As verbs, suppose and guess are synonyms defined as:

Other synonyms of suppose include imagine, opine, reckon, think.

suppose (noun)	guess (noun)
	an estimate based on little or no information
	a message expressing an opinion based on incomplete evidence

suppose (verb)	guess (verb)
expect, believe, or suppose	expect, believe, or suppose
to believe especially on uncertain or tentative grounds	judge tentatively or form an estimate of (quantities or time)
require as a necessary antecedent or precondition	guess correctly; solve by guessing
take for granted or as a given; suppose beforehand	put forward, of a guess, in spite of possible refutation
express a supposition