The word onion first started showing up in the 1350s with a wide variety of spellings, including unniun, huniun, oignon, oinon, and oynun, among others. Everything indicates that it came through Anglo-French from the Old French word oignon, which still referred to the vegetable. Finally, oignon comes straight from the colloquial Latin word unio, literally translating to "united" (from unus, from Proto-Indo-European oynos, "one"). According to Roman writer Columella, peasants gave it that name because it didn't have any shoots and was thus a single entity. The word, which could also mean "pearl", was used in informal situations instead of the usual Latin noun, cepa, which resulted in Romance language names like Italian cipolla and Spanish cebolla.
Hello! I'm Adam Aleksic, a senior studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy trivia, politics, vexillology, geography, board games, conlanging, art history, and law.