guess

[1]	conjecture , estimate , hypothesize , speculate , postulate , (Slang) guestimate/guesstimate
[2]	think , suppose , conclude , assume , believe , dare say , surmise , judge , deem , reckon , imagine , fancy , feel , suspect , divine
[3]	think , opine , suppose , imagine , reckon
[4]	venture , pretend , hazard
[5]	estimate , gauge , approximate , judge
[6]	infer

[1]	conjecture , supposition , surmise , surmisal , speculation , hypothesis
[2]	guesswork , guessing , shot , dead reckoning
[3]	conjecture , estimate , hypothesis , speculation , surmise , assumption , judgement , feeling , suspicion , supposition , postulate , theory , guesswork , (Colloq) shot in the dark , (Slang) guestimate/guesstimate