Plu"mule (?), n. [L. plumula, dim. of pluma a feather; cf. F. plumule.] 1. (Bot.) The first bud, or gemmule, of a young plant; the bud, or growing point, of the embryo, above the cotyledons. See Illust. of Radicle. Gray.

2. (Zoöl.) (a) A down feather. (b) The aftershaft of a feather. See Illust. under Feather. (c) One of the featherlike scales of certain male butterflies.