Source : Webster's Revised Unabridged Dictionary (1913)

Fantail \Fan"tail`\ (f[a^]n"t[=a]l`), n. (Zool.)
   (a) A variety of the domestic pigeon, so called from the
       shape of the tail.
   (b) Any bird of the Australian genus {Rhipidura}, in which
       the tail is spread in the form of a fan during flight.
       They belong to the family of flycatchers.

Source : WordNet®

fantail
     n : an overhang consisting of the fan-shaped part of the deck
         extending aft of the sternpost of a ship