whimsy

英 ['wɪmzɪ] 美['wɪmzi]

1. an odd or fanciful or capricious idea;: "the theatrical notion of disguise is associated with disaster in his stories"; "he had a whimsy about flying to the moon"; "whimsy can be humorous to someone with time to enjoy it"

2. 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"