# allergen

> English word · Noun · IPA /ˈælə(ɹ)ˌd͡ʒɛn/ · frequency rank #45,197

## Definitions
1. A substance which causes an allergic reaction.

## Etymology
Syncopated compound of allergy + -gen, coined on the model of pharmaceutical words such as pathogen and antigen.

## Easily confused with
- **allergy** (https://plainspell.com/en/vs/allergen-vs-allergy)
- **allergic** (https://plainspell.com/en/vs/allergen-vs-allergic)
- **allergies** (https://plainspell.com/en/vs/allergen-vs-allergies)
- **allege** (https://plainspell.com/en/vs/allege-vs-allergen)
- **alleged** (https://plainspell.com/en/vs/alleged-vs-allergen)

## Common misspellings (10)
`alelrgen`, `alergen`, `allegren`, `alleregn`, `allergenn`, `allerggen`, `allergne`, `allerrgen`, `allregen`, `lalergen`

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