The Collaborative International Dictionary of English v.0.48:
Monocotyledonous \Mon`o*cot`y*le"don*ous\, a. [Cf. F. monocotyl['e]don['e].] (Bot.) Having only one cotyledon, seed lobe, or seminal leaf. --Lindley. [1913 Webster]WordNet (r) 3.0 (2006):
monocotyledonous adj 1: (of a flowering plant) having a single cotyledon in the seed as in grasses and lilies [ant: dicotyledonous]