to arrive at or commit oneself to an opinion about (something) without having sufficient evidence to support the opinion fully

to guess a person's weight.

to estimate or conjecture about correctly

to guess what a word means.

to think, believe, or suppose

I guess I can get there in time.

to form an estimate or conjecture (often fol. by at or about )

We guessed at the weight of the package.

to estimate or conjecture correctly.

an opinion that one reaches or to which one commits oneself on the basis of probability alone or in the absence of any evidence whatever.

the act of forming such an opinion

to take a guess at someone's weight.

by guess and by gosh, Northern U.S. using a combination of guesswork and reliance on luck; hit or miss. Also

by guess and by golly.

noun

calculation , measurement

verb

calculate , measure

noun

assumption , ballpark figure * , conclusion , conjecture , deduction , divination , estimate , fancy , feeling , guesstimate , guesswork , hunch * , hypothesis , induction , inference , judgment , notion , opinion , postulate , postulation , prediction , presumption , presupposition , reckoning , shot * , shot in the dark * , sneaking suspicion , stab * , supposal , supposition , surmisal , surmise , suspicion , theory , thesis , view , speculation , augury , estimation , haruspication , prognosis , prognostication , prophesy

verb

believe , calculate , chance , conjecture , dare say , deduce , deem , divine , estimate , fancy * , fathom , go out on a limb , guesstimate , happen upon , hazard * , hypothesize , infer , judge , jump to a conclusion , lump it , opine , penetrate , pick , postulate , predicate , predict , presume , pretend , reason , reckon , select , size up * , solve , speculate , suggest , suppose , surmise , survey , suspect , take a shot at , take a stab at , theorize , think , think likely , venture , work out * , anticipate , apprehend , assert , assume , conclude , daresay , extrapolate , fancy , hunch , imagine , prediction , presage , prognosticate , shot , speculation , stub