Entry 1 sense Webster, 1913 Awn /(a̤n)/ · IPA /ɔːn/ 01 n. The bristle or beard of barley, oats, grasses, etc., or any similar bristlelike appendage; arista. 1. The bristle or beard of barley, oats, grasses, etc., or any similar bristlelike appendage; arista.(Bot.)