Ceba in Catalan
Cebolla in Spanish
بَصَل in Arabic
بَصَل ? بَصَل !
Siepel in Drents (language of the Dutch province of Drenthe).
Ajuin in certain cities in the southern Dutch province of Brabants (esp. Breda, Eindhoven; in other Brabant cities 'juin').
Ûh in Haags (dialect from Den Haag, the city of the Hague, Netherlands).
Louk, lauk, un, oei, ooi, ul'lieg: different words in the southern Dutch province of Limburg (which word is used for 'onion' depends on the city).
Cepo in Esperanto.
پياز in Persian (pronounce: piaz).