Back, against, away
With- is an Old English prefix from "wið" (against, toward, away from) — the historical opposite of the modern preposition "with" (= together). It signals retraction, resistance, or retention: withdraw = pull back/away; withstand = stand firm against; withhold = hold back; wither = dry back/shrink away. The gap between the preposition and the prefix is a common source of confusion for learners.