n. [ L. frustulum, dim. fr. frustum a piece: cf. F. frustule. ] (Bot.) The siliceous shell of a diatom. It is composed of two valves, one overlapping the other, like a pill box and its cover. [ 1913 Webster ]

a. [ L. frustulentus. See Frustule. ] Abounding in fragments. [ R. ] [ 1913 Webster ]