# castellated nut

> English word · Noun

## Definitions
1. A type of nut (internally threaded fastener) with castellations, typically to hold a retaining pin that is passed through a cross-drilled hole, such as a cotter pin.

## Etymology
Physically descriptive via a metaphor; called thus because the slots in the nut — the castellations — have a fancied resemblance to the battlements of a castle.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/castellated-nut