Source : Webster's Revised Unabridged Dictionary (1913)

Whimsicality \Whim`si*cal"i*ty\, n.
   The quality or state of being whimsical; whimsicalness.

Source : WordNet®

whimsicality
     n 1: the trait of acting unpredictably and more from whim or
          caprice than from reason or judgment; "I despair at the
          flightiness and whimsicality of my memory" [syn: {flightiness},
           {arbitrariness}, {whimsy}, {whimsey}, {capriciousness}]
     2: the trait of behaving like an imp [syn: {impishness}, {mischievousness},
         {puckishness}]