# trochoid

> English word · Noun

## Definitions
1. The curve traced by a point on a circle as it rolls along a straight line
2. An organism or fossil with a trochoid shell (especially one in the gastropod family Trochidae), or the shell itself.

## Etymology
From Ancient Greek τροχοειδής (trokhoeidḗs), from τροχός (trokhós, “wheel”) + εἶδος (eîdos, “form, image”).

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