locknut

/ ˈlɒkˌnʌt /

noun

1. a supplementary nut screwed down upon a primary nut to prevent it from shaking loose
2. a threaded nut having a feature, such as a nylon insert, to prevent it from shaking loose

Example Sentences

When the bolt has been screwed down sufficiently tight a locknut may be put on, or the first nut soldered to the end of the bolt.

From Project Gutenberg

A locknut is used beneath the notched nut to hold the adjustment.

From Project Gutenberg

A locknut is used to hold the screw in any desired position.

From Project Gutenberg