Source : Webster's Revised Unabridged Dictionary (1913)

Monocotyledon \Mon`o*cot`y*le"don\, n. [Mono- + cotyledon: cf.
   F. monocotyl['e]done.] (Bot.)
   A plant with only one cotyledon, or seed lobe.

   Note: The plural, monocotyledons, is used as the name of a
         large class of plants, and is generally understood to
         be equivalent to the term endogens.

Source : WordNet®

monocotyledon
     n : a monocotyledonous flowering plant; the stem grows by
         deposits on its inside [syn: {monocot}, {liliopsid}, {endogen}]