翼形螺釘,拇指夾
Thumbscrew \Thumb"screw`\, n. 1. A screw having a flat-sided or knurled head, so that it may be turned by the thumb and forefinger. 2. An old instrument of torture for compressing the thumb by a screw; a thumbkin.
thumbscrew n 1: instrument of torture that crushes the thumb 2: screw designed to be turned with the thumb and fingers