suppose (v.)

late 14c., posicioun, as a term in logic and philosophy, "statement of belief, the laying down of a proposition or thesis," from Old French posicion "position, supposition" (Modern French position) and directly from Latin positionem (nominative positio) "act or fact of placing, situation, position, affirmation," noun of state from past-participle stem of ponere "put, place." Watkins tentatively identifies this as from PIE *po-s(i)nere, from *apo- "off, away" (see apo-) + *sinere "to leave, let" (see site). But de Vaan identifies it as from Proto-Italic *posine-, from PIE *tkine- "to build, live," from root *tkei- "to settle, dwell, be home" (see home (n.)).

The meaning "place occupied by a person or thing" especially a proper or appropriate place, is from 1540s; hence "status, standing, social rank" (1832); "official station, employment" (1890). The meaning "manner in which some physical thing is arranged or posed, aggregate of the spatial relations of a body or figure to other such bodies or figures" is recorded by 1703; specifically in reference to dance steps, 1778, to sexual intercourse, 1883. Military sense of "place occupied or to be occupied" is by 1781.

early 15c., altered from presupponen (c. 1400), "assume beforehand or in the beginning," from Old French presupposer (14c.), formed in French or else from Medieval Latin praesupponere; see pre- + suppose. The meaning "take for granted in advance of actual knowledge or experience" is from 1520s. Related: Presupposed; presupposing.