whimsicality

from WordNet (r) 3.0 (2006)

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}, {whimsicality}, {whimsy},
         {whimsey}, {capriciousness}]
    2: the trait of behaving like an imp [syn: {impishness},
       {mischievousness}, {puckishness}, {whimsicality}]

from The Collaborative International Dictionary of English v.0.48

Whimsicality \Whim`si*cal"i*ty\, n.
   The quality or state of being whimsical; whimsicalness.
   [1913 Webster]