mid-14c., "a setting forth as a topic for discussion," from Old French proposicion "proposal, submission, (philosophical) proposition" (12c.), from Latin propositionem (nominative propositio) "a setting forth, statement, a presentation, representation; fundamental assumption," noun of action from past participle stem of proponere (see propound). Meaning "action of proposing something to be done" is from late 14c. General sense of "matter, problem, undertaking" recorded by 1877. Related: Propositional.
1914, from proposition (n.); specifically of sexual favors from 1936. Related: Propositioned; propositioning.