资料来源 : Webster's Revised Unabridged Dictionary (1913)

Thrashing \Thrash"ing\,
   a. & n. from {Thrash}, v.

   {Thrashing floor}, {Threshing-floor}, or {Threshing floor}, a
      floor or area on which grain is beaten out.

   {Thrashing machine}, a machine for separating grain from the
      straw.

资料来源 : WordNet®

threshing floor
     n : a floor or ground area for threshing or treading out grain