# auxin

> English word · Noun · frequency rank #76,550

## Definitions
1. A class of plant growth substance (often called phytohormones or plant hormones) which play an essential role in coordination of many growth and behavioral processes in the plant life cycle.

## Etymology
From Ancient Greek αὐξάνω (auxánō, “to grow”) + -in.

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