Mawson, C.O.S., ed. (1870–1938). Roget’s International Thesaurus. 1922.

Class IV. Words Relating to the Intellectual Faculties
Division (I) Formation of Ideas
Section VII. Creative Thought

514. Supposition.

   NOUN:SUPPOSITION, assumption, supposal, supposableness [rare], suppositality [obs.], postulation [rare], condition, presupposition, hypothesis, postulate, postulatum, theory, data; proposition, position; thesis, theorem; proposal (plan) [See Plan]; assumed position.
  bare -, vague -, loose- -supposition, – suggestion; conceit; conjecture; guess, guesswork; rough guess, shot [colloq.]; conjecturality [rare], suggestiveness, presurmise, surmise, suspicion, inkling, suggestion, association of ideas, hint; presumption (belief) [See Belief]; divination, speculation.
  THEORIST, theorizer, speculatist [rare], speculator, notionalist, hypothesist, hypothetist [rare], doctrinaire, doctrinarian.
   VERB:SUPPOSE, conjecture, surmise, suspect, guess, divine; theorize; presume, presuppose; assume, fancy, wis [archaic], take it; give a guess, speculate, believe, dare say, take it into one’s head, take for granted.
  PROPOUND, propose, put forth; start, put a case, submit, move, make a motion; hazard -, venture -, throw out -, put forward- a -suggestion, – conjecture, – supposition; hypothesize.
  SUGGEST, allude to, hint, put it into one’s head.
  suggest itself (thought) [See Thought]; run in the head (memory) [See Memory]; marvel -, wonder- -if, – whether.
   ADJECTIVE:SUPPOSING &c. v.; given, mooted, postulatory [now rare]; assumed &c. v.; suppositive, supposititious; gratuitous, speculative, conjectural, conjecturable, hypothetical, theoretical, academic, supposable, presumptive, putative; suppositional, suppositionary.
  SUGGESTIVE, allusive, stimulating.
   ADVERB:IF, if so be; an [archaic]; on the supposition &c. n.; ex hypothesi [L.], in case, in the event of; if that [archaic], so that, whether; quasi, as if, provided; perhaps (by possibility) [See Possibility]; for aught one knows.