N-VAR
一时的兴致;心血来潮;突发的奇想
A whim is a wish to do or have something which seems to have no serious reason or purpose behind it, and often occurs suddenly.
例句
We decided, more or less on a whim, to sail to Morocco...
我们多少有点心血来潮，决定航海去摩洛哥。
The premium can increase at the whim of the insurers...
保险公司可以随时提高保费。