1. a screw with a head that can be turned by thumb and finger without tools
2. an instrument of torture that crushes the thumbs
Usage: historical

Examples

• The camera tripod uses thumbscrews for easy adjustment without tools.
• She tightened the thumbscrew on the clamp with her fingers.
• The equipment case has thumbscrews for quick access to the contents.
• Medieval torture devices included the thumbscrew among other cruel instruments.
• The thumbscrew mechanism allows for precise positioning of the microscope stage.
• He loosened the thumbscrews to remove the panel cover.