guesswork vs guess

guesswork and guess both are nouns.

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

As nouns, guesswork and guess are synonyms defined as:

Other synonyms of guesswork include dead reckoning, guessing, shot.

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

guesswork (verb)	guess (verb)
	expect, believe, or suppose
	judge tentatively or form an estimate of (quantities or time)
	guess correctly; solve by guessing
	put forward, of a guess, in spite of possible refutation