Source : Webster's Revised Unabridged Dictionary (1913)

Darnel \Dar"nel\, n. [OE. darnel, dernel, of uncertain origin;
   cf. dial. F. darnelle, Sw. d[*a]r-repe; perh. named from a
   supposed intoxicating quality of the plant, and akin to Sw.
   d[*a]ra to infatuate, OD. door foolish, G. thor fool, and Ee.
   dizzy.] (Bot.)
   Any grass of the genus {Lolium}, esp. the {Lolium temulentum}
   (bearded darnel), the grains of which have been reputed
   poisonous. Other species, as {Lolium perenne} (rye grass or
   ray grass), and its variety {L. Italicum} (Italian rye
   grass), are highly esteemed for pasture and for making hay.

   Note: Under darnel our early herbalists comprehended all
         kinds of cornfield weeds. --Dr. Prior.

Source : WordNet®

darnel
     n : weedy annual grass often occurs in grainfields and other
         cultivated land; seeds sometimes considered poisonous
         [syn: {tare}, {bearded darnel}, {cheat}, {Lolium
         temulentum}]