The noun whim has 2 senses (first 1 from tagged texts)
1. (1) caprice, impulse, whim -- (a sudden desire; "he bought it on an impulse")
2. notion, whim, whimsy, whimsey -- (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")