\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. (Zo["o]l.)
   (a) A down feather.
   (b) The aftershaft of a feather. See Illust. under
       {Feather}.
   (c) One of the featherlike scales of certain male
       butterflies.