Noun

• S: (n) guess, conjecture, supposition, surmise, surmisal, speculation, hypothesis (a message expressing an opinion based on incomplete evidence)
• direct hyponym / full hyponym
• direct hypernym / inherited hypernym / sister term
• derivationally related form

Verb

• S: (v) surmise (infer from incomplete evidence)
• S: (v) suspect, surmise (imagine to be the case or true or probable) "I suspect he is a fugitive"; "I surmised that the butler did it"