Definition of: guess

(ges) v.t.
1. To form a judgment or opinion of (something) on uncertain or incomplete knowledge; surmise; conjecture.
2. To conjecture correctly: to guess the answer.
3. To believe; think: I guess we'll be late.
—v.i.
4. To form a judgment or opinion on uncertain or incomplete knowledge.
5. To conjecture correctly: How did you guess?
—noun
1. A tentative opinion or conclusion; a supposition; surmise; conjecture.
2. The act of guessing. [ME gessen, prob. <Scand. Cf. Sw. gissa, Dan. gisse guess.]
—guess′er noun Synonyms (verb): conjecture, divine, fancy, imagine, suppose, surmise, suspect. See SOLVE, SUPPOSE. Antonyms: demonstrate, establish, prove. Synonyms (noun): conjecture, hypothesis, supposition, surmise. A guess is a conclusion from data directly at hand, and held as probable or tentative, while one confessedly lacks material for certainty. A conjecture is preliminary and tentative, but more methodical than a guess; a supposition is more nearly final; a surmise is an imagination or a suspicion. Antonyms: assurance, certainty, confidence, conviction, demonstration, proof.