# hardener

> English word · Noun · IPA /ˈhɑɹdn̩ɚ/

## Definitions
1. One who, or that which, hardens.
2. A chemical substance added to something in order to harden it; used especially with paints, varnishes and resins.

## Etymology
From harden + -er.

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