# rachis

> English word · Noun · IPA /ˈɹeɪkɪs/ · frequency rank #94,161

## Definitions
1. The spinal column, or the vertebrae of the spine.
2. An anatomical shaft or axis in a marine invertebrate.
3. The central shaft of a feather.
4. The axis of either a compound leaf, inflorescence, or fern frond.

## Etymology
From New Latin rachis, from Ancient Greek ῥάχις (rhákhis, “spine, ridge”).

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