The Collaborative International Dictionary of English v.0.48:
Aleurone \A*leu"rone\, n. [Gr. ? flour.] (Bot.) An albuminoid substance which occurs in minute grains ("protein granules") in maturing seeds and tubers; -- supposed to be a modification of protoplasm. [1913 Webster]WordNet (r) 3.0 (2006):
aleurone n 1: granular protein in outermost layer of endosperm of many seeds or cereal grains