1. [ noun ] the trait of acting unpredictably and more from whim or caprice than from reason or judgment
Synonyms: arbitrariness whimsy whimsey capriciousness flightiness

"I despair at the flightiness and whimsicality of my memory"

Related terms: irresponsibility
2. [ noun ] the trait of behaving like an imp
Synonyms: mischievousness puckishness impishness
Related terms: playfulness
Similar spelling:   whimsical