(Science: botany) A liliaceous plant of the genus allium (A.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.
Origin: F. Ognon, fr. L. Unio oneness, unity, a single large pearl, an onion. See One, Union.