What does thumbscrew mean?
A thumbscrew is a small fastener, such as a screw or nut, whose head is shaped so that it can be turned by hand. This makes it especially useful on equipment, camera mounts, laboratory apparatus, and other places where a tool would be inconvenient to use. The word's name plainly describes the principle: the screw is tightened with the thumb, usually with the fingers assisting. In a separate historical sense, a thumbscrew was an instrument used to crush or torture a person's thumbs and fingers. The modern mechanical meaning is much more common, but the darker sense gives the word a memorable contrast between an ordinary practical object and a cruel device. The term is used in both British and American English, with technical contexts often preferring the broader expression “wing nut.”
nounA thumbscrew is a screw or nut with a flattened, winged, or projecting head designed to be tightened or loosened by hand. Historically, the word also denotes an instrument used to crush a person's fingers or thumbs.
- A screw, nut, or fastener with a head that can be turned by the fingers, usually without a separate tool.
- An instrument, especially in historical accounts of torture, used to compress or crush the thumbs or fingers.
"He loosened the thumbscrew on the tripod until the camera stopped wobbling."
"The technician tightened the thumbscrew and secured the metal panel in place."
"The museum display explains how a thumbscrew was used to torture prisoners by crushing their thumbs."
The regular plural is formed by adding -s.
"The instructions call for two thumbscrews to secure the cover."
One word spans both the workshop and the dungeon: a thumbscrew can be a handy hand-tightened fastener or a notorious torture instrument.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of thumbscrew
Thumbscrew is an English compound formed from “thumb” and “screw.” In its mechanical sense, the name refers to a screw or fastener operated with the thumb and fingers. The same compound has also been used for a device that compresses the thumb or fingers as a form of torture.
How thumbscrew is actually used
In mechanical contexts, the term is often close in meaning to “wing nut,” though a thumbscrew may have a flattened or projecting head rather than distinct wings. The torture sense is historical and usually appears in discussions of historical violence or instruments of punishment.