whim

noun3

1. •
   A fanciful impulse, or sudden change of idea.

   • Let ev’ry Man enjoy his whim; / What’s He to Me, or I to him? — 1763
2. •
   A large capstan or vertical drum turned by horse power or steam power, for raising ore or water, etc., from mines, or for other purposes.
3. •
   A bird, the Eurasian wigeon.

verb1

1. •
   (rare) To be seized with a whim; to be capricious.

noun1

1. •
   Initialism of warm-hot intergalactic medium.