castle nut

American

noun

castellated nut.

castle nut British

noun

a hexagonal nut with six slots in the head, two of which take a locking pin to hold it firmly in position

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of castle nut

First recorded in 1900–05

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

And they have given their homes whimsical names such as Sea Castle, Nut House and A Turn of Fraise.

From Los Angeles Times

Underneath, you'll find a little castle nut that you'll remove.

From Time Magazine Archive

Remove the castle nut and dust seal, and then drop the bottom clamp out of the frame.

From Time Magazine Archive

Making sure that the bearings are sitting properly and not bound up, put the top dust seal back in place and then thread the castle nut onto the steering stem.

From Time Magazine Archive

Tighten the castle nut as tight as you can get it with your hand and a rag.

From Time Magazine Archive

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023