porc-espin

Old French porc-espin combines porc ('pig') and espin ('spine, thorn'), from Latin porcus ('pig') and spina ('thorn'). The construction is perfectly descriptive: a pig with thorns. Italian istrice took a different approach, deriving from Latin hystrix, from Greek hystrix (ὕστριξ), meaning 'bristle.' Two languages, two strategies: one saw a thorny pig, the other saw a bristle.

The Romans knew porcupines well. North African crested porcupines (Hystrix cristata) were present in Italy — and may have been introduced for arena spectacles. Pliny described them in his Natural History, noting correctly that the quills were modified hairs and incorrectly that the animal could shoot them at attackers. The shooting myth persisted in European natural history for centuries.

English borrowed porcupine from Old French by the 1400s, with spelling variations including porpentine (which Shakespeare used in Hamlet, 1600). The word stabilized as 'porcupine' by the 1700s. The two major groups — Old World porcupines (family Hystricidae) and New World porcupines (family Erethizontidae) — are not closely related. The name was applied to both because they both have quills and both, to European eyes, looked like thorny pigs.

Porcupine quills cannot be shot. They detach easily on contact, and their barbed tips make them difficult to remove — which is worse, from the predator's perspective, than being shot at. The quills are antibiotic-coated, which protects the porcupine from infection if it accidentally stabs itself (which happens). The thorny pig is better engineered than the myth suggests.