WordWeb Online

1. The quality of being guided by sudden unpredictable impulses
   - unpredictability
    
2. The trait of acting unpredictably and more from whim or caprice than from reason or judgment
   "I despair at the capriciousness and whimsicality of my memory";
   - flightiness, arbitrariness, whimsicality, whimsy, whimsey

Type of: changefulness, inconstancy, irresponsibility, irresponsibleness