# hapten

> English word · Noun

## Definitions
1. Any small molecule that can elicit an immune response only when attached to a large carrier such as a protein.

## Etymology
Early 20th century: from German Hapten, from Ancient Greek ἅπτειν (háptein, “to fasten”).

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