On·ion n.
 1. Bot. A liliaceous plant of the genus Allium (Allium cepa), having a strong-flavored bulb and long hollow leaves; also, its bulbous root, much used as an article of food.  The name is often extended to other species of the genus.
 Onion fish Zool., the grenadier.
 Onion fly Zool. a dipterous insect whose larva feeds upon the onion; especially, Anthomyia ceparum and Ortalis flexa.
 Welsh onion. Bot. See Cibol.
 Wild onion Bot., a name given to several species of the genus Allium.

 ◄ ►


 wild onion
      n : any of various plants of the genus Allium with edible bulbs
          found growing wild