# rotula

> English word · Noun

## Definitions
1. The patella; the kneecap.
2. One of the five radial pieces in the dentary apparatus of the sea urchin.

## Etymology
Learned borrowing from Latin rotula. Doublet of role and roll.

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