From Old English wrencan 'to twist' — the tool was named for its twisting action.
A tool used for gripping and turning nuts, bolts, or pipes.
From Old English wrencan 'to twist, turn,' from Proto-Germanic *wrankijaną. The noun meaning 'act of twisting' appeared in Middle English; the tool sense developed in the 17th century because the tool works by twisting. Key roots: *wer- (Proto-Indo-European: "to turn, bend").