1630s, from Latin vicarius "substitute, deputy" (adj. and n.), from vicis "turn, change, exchange, substitution," from PIE root *weik-, *weig- "to bend, wind" (cf. Sanskrit visti "changing, changeable;" Old English wician "to give way, yield," wice "wych elm;" Old Norse vikja "to bend, turn;" Swedish viker "willow twig, wand;" German wechsel "change"). Related: Vicariously.