supposition

/ˈsʌpəˌzɪʃən/

/səpəˈzɪʃən/

Other forms: suppositions

A supposition is a guess or a hypothesis. Your supposition that your kids will automatically wash their hands before dinner is probably false. You'd best remind them to do it or risk dirty hands at dinner.

What's the difference between an assumption and a supposition — both nouns that are often taken as synonyms for each other? An assumption is an idea or theory that is usually made without proof. A supposition, on the other hand, has the connotation that the idea or theory is testable and provable. If you are to meet someone named Hunter, you may make the assumption that you are meeting a man. But if you know that Hunter lives in an all-female dorm, you may have the supposition that Hunter is a woman.

Definitions of supposition

1. noun

   the cognitive process of supposing
   synonyms: supposal

   types:

   presupposition

   the act of presupposing; a supposition made prior to having knowledge (as for the purpose of argument)

   type of:

   conjecture

   reasoning that involves the formation of conclusions from incomplete evidence
2. noun

   a message expressing an opinion based on incomplete evidence
   synonyms: conjecture, guess, hypothesis, speculation, surmisal, surmise

   types:

   divination

   successful conjecture by unusual insight or good luck

   type of:

   opinion, view

   a message expressing a belief about something; the expression of a belief that is held with confidence but not substantiated by positive knowledge or proof
3. noun

   a hypothesis that is taken for granted
   synonyms: assumption, supposal

   types:

   conclusion

   an intuitive assumption

   base, basis, cornerstone, foundation, fundament, groundwork

   the fundamental assumptions from which something is begun or developed or calculated or explained

   given, precondition, presumption

   an assumption that is taken for granted

   basic assumption, constatation, self-evident truth

   an assumption that is basic to an argument

   non sequitur

   (logic) a conclusion that does not follow from the premises

   meat and potatoes

   the fundamental part

   type of:

   hypothesis, possibility, theory

   a tentative insight into the natural world; a concept that is not yet verified but that if true would explain certain facts or phenomena