from
The Collaborative International Dictionary of English v.0.48
Onion \On"ion\, n. [F. ognon, fr. L. unio oneness, unity, a
single large pearl, an onion. See {One}, {Union}.]
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.
[1913 Webster]
2. The flavor of an onion[1].
[PJC]
{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}.
[1913 Webster]