al•eu•rone(al′yə rōn′, ə lŏŏr′ōn),USA pronunciationn. (in the seeds of cereal plants)protein granules (al′eurone grains′) found in a single layer of cells (al′eurone lay′er) USA pronunciation in the outermost portion of the endosperm.Also, al•eu•ron(al′yə ron′, ə lŏŏr′on).USA pronunciation