The Collaborative International Dictionary of English v.0.48:

Pintail \Pin"tail`\, n.
   1. (Zool.) A northern duck (Dafila acuta), native of both
      continents. The adult male has a long, tapering tail.
      Called also gray duck, piketail, piket-tail,
      spike-tail, split-tail, springtail, sea pheasant,
      and gray widgeon.
      [1913 Webster]

   2. (Zool.) The sharp-tailed grouse of the great plains and
      Rocky Mountains (Pedioc[ae]tes phasianellus); -- called
      also pintailed grouse, pintailed chicken,
      springtail, and sharptail.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Springtail \Spring"tail`\ (-t[=a]l`), n. (Zool.)
   Any one of numerous species of small apterous insects
   belonging to the order Thysanura. They have two elastic
   caudal stylets which can be bent under the abdomen and then
   suddenly extended like a spring, thus enabling them to leap
   to a considerable distance. See Collembola, and Podura.
   [1913 Webster]

WordNet (r) 3.0 (2006):

springtail
    n 1: any of numerous minute wingless primitive insects
         possessing a special abdominal appendage that allows the
         characteristic nearly perpetual springing pattern; found in
         soil rich in organic debris or on the surface of snow or
         water [syn: collembolan, springtail]