thumbscrew

thumbscrew

1. an instrument of torture that pinches or crushes the thumbs

2. a screw with projections on its head enabling it to be turned by the thumb and forefinger

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

thumbscrew

[′thəm‚skrü]

(design engineering)

A screw with a head flattened in the same axis as the shaft so that it can be gripped and turned by the thumb and forefinger.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

thumbscrew

A screw having a broad head that is knurled or flattened so that it may be turned easily by the thumb and one finger.

McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.