whimsicality

Noun

• the trait of behaving like an imp

• 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
    

Related words

• Synonyms: 
  impishness , mischievousness , puckishness , flightiness , arbitrariness , whimsy , whimsey , capriciousness