WordWeb Online

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"; "I despair at the arbitrariness and whimsicality of my memory"; "I despair at the whimsy and whimsicality of my memory"; "I despair at the whimsey and whimsicality of my memory"; "I despair at the capriciousness and whimsicality of my memory"
   - flightiness, arbitrariness, whimsy, whimsey, capriciousness
    
2. The trait of behaving like an imp
   - impishness, mischievousness, puckishness

Derived forms: whimsicalities

See also: whimsical

Type of: fun, irresponsibility, irresponsibleness, playfulness