From a hypothetical Old French *eriz, from Latin erīcius (“hedgehog”), with the suffix -on added later. Another possibilty may be a Vulgar Latin root *erīcio, ericione, but this would have seemingly produced an *erçon in Old French. Compare, however, Catalan eriçó and Romansch erizun. See also oursin.
- “hérisson” in le Trésor de la langue française informatisé (The Digitized Treasury of the French Language).