Meaning

verb express a supposition

verb expect, believe, or suppose

verb to believe especially on uncertain or tentative grounds

originFrom Middle English supposen, borrowed from Old French supposer, equivalent to prefix sub- (“under”) + poser (“to place”); corresponding in meaning to Latin supponere (“to put under, to substitute, falsify, counterfeit”), suppositum. See pose.

Etymology from Wiktionary, CC BY-SA 3.0