The Collaborative International Dictionary of English v.0.48:

Zea \Ze"a\ (z[=e]"[.a]), n. [L., a kind of grain, fr. Gr. ze`a,
   zeia`; cf. Skr. yava barley.] (Bot.)
   A genus of large grasses of which the Indian corn (Zea
   Mays) is the only species known. Its origin is not yet
   ascertained. See Maize.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Zein \Ze"in\, n. [Cf. F. z['e]ine. See Zea.] (Chem.)
   A nitrogenous substance of the nature of gluten, obtained
   from the seeds of Indian corn (Zea) as a soft, yellowish,
   amorphous substance. [Formerly written zeine.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

Zea
    n 1: corn [syn: Zea, genus Zea]