Thumbscrew

['θʌmskruː] or ['θʌmskru]

(noun.) screw designed to be turned with the thumb and fingers.

(noun.) instrument of torture that crushes the thumb.

Editor: Moll--From WordNet

(n.) A screw having a flat-sided or knurled head, so that it may be turned by the thumb and forefinger.

(n.) An old instrument of torture for compressing the thumb by a screw; a thumbkin.

Checked by Elaine