# active ingredient

> English word · Noun

## Definitions
1. The specific compound in a natural or man-made mixture that is responsible for the mixture's activity.
2. The essence of something, or a sine qua non that it requires.

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