From WordNet (r) 2.0 (August 2003) [wn]:
leek
n 1: plant having a large slender white bulb and flat overlapping
dark green leaves; used in cooking; believed derived
from the wild Allium ampeloprasum [syn: scallion,
Allium porrum]
2: related to onions; white cylindrical bulb and flat
dark-green leaves
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Leek \Leek\ (l[=e]k), n. [AS. le['a]c; akin to D. look, G.
lauch, OHG. louh, Icel. laukr, Sw. l["o]k, Dan l["o]g. Cf.
Garlic.] (Bot.)
A plant of the genus Allium (Allium Porrum), having
broadly linear succulent leaves rising from a loose oblong
cylindrical bulb. The flavor is stronger than that of the
common onion.
[1913 Webster]
Wild leek, in America, a plant (Allium tricoccum) with a
cluster of ovoid bulbs and large oblong elliptical leaves.
[1913 Webster]