supposing

UK: /səˈpəʊzɪŋ/ US: (sə pō′zing)

From the verb suppose: (⇒ conjugate)

supposing is: ⓘ

v pres p

WordReference Random House Unabridged Dictionary of American English © 2026

sup•pos•ing  (sə pō′zing), conj. 

1. upon the supposition or premise that;
   in the event that.

• see suppose, -ing² 1835–45

WordReference Random House Learner's Dictionary of American English © 2026

sup•pose /səˈpoʊz/   v., -posed, -pos•ing, conj. 
v. [not: be + ~-ing]

1. to assume (something), as for the sake of argument:
   [~ + (that) clause] Suppose (that) you won a million dollars in the lottery.
2. to think or hold as an opinion;
   believe: [~ + (that) clause]
   What do you suppose (that) he will do?
   [no object]
   Oh, I suppose (so).
3. to believe or assume as true;
   take for granted:
   [~ + (that) clause] We all supposed that he had died in the crash.
4. to expect or require:
   [be + ~-ed + to + verb] The machine is not supposed to make noise.

conj. 

5. Also, supposing. (used to put forward or evaluate something to be considered as a possibility):
   Suppose (supposing) we do wait until tomorrow; what then?

See -pos-.

WordReference Random House Unabridged Dictionary of American English © 2026

sup•pose  (sə pōz′), v., -posed, -pos•ing. 
v.t. 

1. to assume (something), as for the sake of argument or as part of a proposition or theory:
   Suppose the distance to be one mile.
2. to consider (something) as a possibility suggested or an idea or plan proposed:
   Suppose we wait until tomorrow.
3. to believe or assume as true;
   take for granted:
   It is supposed that his death was an accident.
4. to think or hold as an opinion:
   What do you suppose he will do?
5. to require logically;
   imply;
   presuppose:
   The evidence supposes his presence near the scene.
6. (used in the passive) to expect or design;
   require or permit (fol. by an infinitive verb):
   The machine is supposed to make noise. I'm not supposed to run fast.

v.i. 

7. to assume something;
   presume;
   think.

• Old French supposer, equivalent. to sup- sup- + poser to pose¹; compare Medieval Latin suppōnere to suppose, Latin: to substitute, place below
• Middle English supposen 1275–1325

sup•pos′a•ble, adj. 
sup•pos′a•bly, adv. 
sup•pos′er, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

suppose / səˈpəʊz/ verb (tr; may take a clause as object)

1. to presume (something) to be true without certain knowledge: I suppose he meant to kill her
2. to consider as a possible suggestion for the sake of discussion, elucidation, etc; postulate: suppose that he wins the election
3. (of theories, propositions, etc) to imply the inference or assumption (of): your policy supposes full employment

Etymology: 14th Century: from Old French supposer, from Medieval Latin suppōnere, from Latin: to substitute, from sub- + pōnere to put

supˈposable adjective

supˈposer noun