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

Falling \Fall"ing\, a. & n.
   from {Fall}, v. i.

   {Falling away}, {Falling off}, etc. See {To fall away}, {To
      fall off}, etc., under {Fall}, v. i.

   {Falling band}, the plain, broad, linen collar turning down
      over the doublet, worn in the early part of the 17th
      century.

   {Falling sickness} (Med.), epilepsy. --Shak.

   {Falling star}. (Astron.) See {Shooting star}.

   {Falling stone}, a stone falling through the atmosphere; a
      meteorite; an a["e]rolite.

   {Falling tide}, the ebb tide.

   {Falling weather}, a rainy season. [Colloq.] --Bartlett.

资料来源 : WordNet®

falling off
     n : a noticeable deterioration in performance or quality; "the
         team went into a slump"; "a gradual slack in output"; "a
         drop-off in attendance"; "a falloff in quality" [syn: {slump},
          {slack}, {drop-off}, {falloff}]