‖/mhw>, n. [ From LL. arilli dry grapes, perh. fr. L. aridus dry: cf. F, . arille. ] (Bot.) A exterior covering, forming a false coat or appendage to a seed, as the loose, transparent bag inclosing the seed of the white water lily. The mace of the nutmeg is also an aril. Gray. [ 1913 Webster ]