thumbscrew (thumskro)

1. A screw having a broad head, or a plate projecting from the head, so that it may be turned easily by the finger and thumb.-2. An instrument of tor ture by which one or both thumbs were compre ed so as to inflict great agony without danger to life. It consisted of a frame with three uprights or bars, between which the thumbs were pa ed; a piece sliding on the bars was forced down upon the thumbs by turning a screw. Thumb-screw, 2.