guess vs surmise

guess and surmise both are nouns.

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

As nouns, guess and surmise are synonyms defined as:

guess and surmise: a message expressing an opinion based on incomplete evidence

Other synonyms of guess include conjecture, hypothesis, speculation, supposition, surmisal.

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

Other hyponyms of guess include anticipate, call, forebode, foretell, predict, prognosticate, promise, suspect.

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

guess (verb)	surmise (verb)
expect, believe, or suppose	infer from incomplete evidence
judge tentatively or form an estimate of (quantities or time)	imagine to be the case or true or probable
guess correctly; solve by guessing
put forward, of a guess, in spite of possible refutation