Source : Webster's Revised Unabridged Dictionary (1913)

Fly \Fly\, n.; pl. {Flies} (fl[imac]z). [OE. flie, flege, AS.
   fl[=y]ge, fle['o]ge, fr. fle['o]gan to fly; akin to D. vlieg,
   OHG. flioga, G. fliege, Icel. & Sw. fluga, Dan. flue. [root]
   84. See {Fly}, v. i.]
   1. (Zo["o]l.)
      (a) Any winged insect; esp., one with transparent wings;
          as, the Spanish fly; firefly; gall fly; dragon fly.
      (b) Any dipterous insect; as, the house fly; flesh fly;
          black fly. See {Diptera}, and Illust. in Append.

   2. A hook dressed in imitation of a fly, -- used for fishing.
      ``The fur-wrought fly.'' --Gay.

Source : WordNet®

flies
     n : (theater) the space over the stage (out of view of the
         audience) used to store scenery (drop curtains)