Wrest, n. 1. The act of wresting; a wrench; a violent twist; hence, distortion; perversion. Hooker.
2. Active or moving power. Spenser.
3. A key to tune a stringed instrument of music.
The minstrel... wore round his neck a silver chain, by which hung the wrest, or key, with which he tuned his harp. Sir W. Scott.
4. A partition in a water wheel, by which the form of the buckets is determined.
Wrest pin(Piano Manuf.), one of the pins around which the ends of the wires are wound in a piano. Knight. — Wrest plank(Piano Manuf.), the part in which the wrest pins are inserted.