Source : Webster's Revised Unabridged Dictionary (1913)

Awn \Awn\, n. [OE. awn, agune, from Icel. ["o]gn, pl. agnir;
   akin to Sw. agn, Dan. avne, Goth. ahana, OHG. agana, G. agen,
   ahne, chaff, Gr. ?, AS. egla; prob. from same root as E.
   acute. See 3d {Ear}. ?1.] (Bot.)
   The bristle or beard of barley, oats, grasses, etc., or any
   similar bristlelike appendage; arista. --Gray.

Source : WordNet®

awn
     n : slender bristlelike appendage found on the bracts of grasses