1. (Science: zoology) 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.
2. (Science: zoology) The sharp-tailed grouse of the great plains and rocky mountains (Pediocaetes phasianellus); called also pintailed grouse, pintailed chicken, springtail, and sharptail.