1 assume, esp. in default of knowledge; be inclined to think (I suppose they will return; what do you suppose he meant?).
2 take as a possibility or hypothesis (let us suppose you are right).
3 (in imper.) as a formula of proposal (suppose we go to the party).
4 (of a theory or result etc.) require as a condition (design in creation supposes a creator).
5 (in imper. or pres. part. forming a question) in the circumstances that; if (suppose he won't let you; supposing we stay).
6 (as supposed adj.) generally accepted as being so; believed (his supposed brother; generally supposed to be wealthy).
7 (in passive; foll. by to + infin.) a be expected or required (was supposed to write to you). b (with neg.) not have to; not be allowed to (you are not supposed to go in there).
Phrases and idioms:
I suppose so an expression of hesitant agreement.
Derivatives:
supposable adj.
Etymology: ME f. OF supposer (as SUB-, POSE(1))
Useful english dictionary. 2012.