aftershaft

from WordNet (r) 3.0 (2006)

aftershaft
    n 1: a supplementary feather (usually small) on the underside of
         the base of the shaft of some feathers in some birds

from The Collaborative International Dictionary of English v.0.48

Hypoptilum \Hy*pop"ti*lum\, n.; pl. L. {Hypoptila}, E.
   {Hypoptilums}. [NL., fr. Gr. "ypo` beneath + ? down.] (Zool.)
   An accessory plume arising from the posterior side of the
   stem of the contour feathers of many birds; -- called also
   {aftershaft}. See Illust. of {Feather}.
   [1913 Webster]

from The Collaborative International Dictionary of English v.0.48

Aftershaft \Aft"er*shaft`\, n. (Zool.)
   The {hypoptilum}.
   [1913 Webster]

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