Source : Webster's Revised Unabridged Dictionary (1913)

Spurious \Spu"ri*ous\, a. [L. spurius.]
   1. Not proceeding from the true source, or from the source
      pretended; not genuine; false; adulterate.

   2. Not legitimate; bastard; as, spurious issue. ``Her
      spurious firstborn.'' --Milton.

   {Spurious primary}, or {Spurious quill} (Zo["o]l.), the
      first, or outer, primary quill when rudimentary or much
      reduced in size, as in certain singing birds.

   {Spurious wing} (Zo["o]l.), the bastard wing, or alula.

   Syn: Counterfeit; false; adulterate; supposititious;
        fictitious; bastard. -- {Spu"ri*ous*ly}, adv. --
        {Spu"ri*ous*ness}, n.

Source : WordNet®

spurious wing
     n : tuft of small stiff feathers on the first digit of a bird's
         wing [syn: {bastard wing}, {alula}]