[syn: decrease, lessening, drop-off]
The Collaborative International Dictionary of English v.0.48:
drop-off \drop-off\ n.
   1. a noticeable decline in performance; as, a drop-off in
      attendance. [WordNet sense 1]
   Syn: slump, falloff, falling off.
        [WordNet 1.5]
   2. a steep high face of rock.
   Syn: cliff. [WordNet sense 2]
        [WordNet 1.5]
   3. a change downward; as, there was a sharp drop-off in
      sales. [WordNet sense 3]
   Syn: decrease, lessening.
        [WordNet 1.5]
WordNet (r) 3.0 (2006):
drop-off
    n 1: 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, falling off]
    2: a steep high face of rock; "he stood on a high cliff
       overlooking the town"; "a steep drop" [syn: cliff, drop,
       drop-off]
    3: a change downward; "there was a decrease in his temperature
       as the fever subsided"; "there was a sharp drop-off in sales"
       [syn: decrease, lessening, drop-off] [ant: increase]