'onion' originates from Latin, specifically the word 'unio,' where 'unio' meant 'single or unity,' referring to the single bulb.

'unio' transformed into the Old French word 'oignon,' and eventually became the modern English word 'onion' through Middle English.

Initially, it meant 'single bulb,' but over time it evolved into its current meaning of 'edible bulb of the onion plant.'