What is the meaning of Whimsy?

A quaint and fanciful idea; a whim; playfully odd behaviour.

An impulsive, illogical or capricious character.

A whim (capstan or vertical drum).

A jigsaw puzzle piece that has been cut into a recognizable shape, as if on a whim; often the shape is representative of the theme of the image used for the puzzle.

To fill with whimsies or whims; to make fantastic; to craze.

Source: wiktionary.org