unhand (v.)

prefix of reversal, deprivation, or removal (as in unhand, undo, unbutton), Old English on-, un-, from Proto-Germanic *andi- (source also of Old Saxon ant-, Old Norse and-, Dutch ont-, Old High German ant-, German ent-, Gothic and- "against"), from PIE *anti "facing opposite, near, in front of, before, against" (from PIE root *ant- "front, forehead," with derivatives meaning "in front of, before").

More or less confused with un- (1) through similarity in the notions of "negation" and "reversal;" an adjective such as unlocked might represent "not locked" (un- (1)) or the past tense of unlock (un- (2)).

c. 1400, "take charge of, seize," from hand (n.). Earlier verbs were hend (Old English genehdan), handle. Meaning "to pass (something to someone)" is from 1640s. To hand it to (someone) "acknowledge someone's ability or superiority" is slang from 1906, the it perhaps meant to suggest a trophy cup, award, etc. Related: Handed; handing.