Source : Webster's Revised Unabridged Dictionary (1913)

Abruptness \Ab*rupt"ness\, n.
   1. The state of being abrupt or broken; craggedness;
      ruggedness; steepness.

   2. Suddenness; unceremonious haste or vehemence; as,
      abruptness of style or manner.

Source : WordNet®

abruptness
     n 1: an abrupt discourteous manner [syn: {brusqueness}, {curtness},
           {gruffness}, {shortness}]
     2: the property possessed by a slope that is very steep [syn: {precipitousness},
         {steepness}] [ant: {gradualness}]
     3: the quality of happening with headlong haste or without
        warning [syn: {precipitateness}, {precipitance}, {precipitancy},
         {suddenness}]