Sport.

Constable, Cloud Study, 1821

An great analogy to learning, with experience being water, the learner being wind, and understanding becoming "the sport of wind," clouds ...

Since the increased attention which has been given to Meteorology, the study of the various appearances of water suspended in the Atmosphere is become an interesting and even necessary branch of that pursuit. If Clouds were the mere result of the condensation of Vapour in the masses of atmosphere which they occupy, if their variations were produced by the movements of the atmosphere alone, then indeed might the study of them be deemed an useless pursuit of shadows, an attempt to describe forms which, being the sport of winds, must be ever varying, and therefore not to be defined. But however the erroneous admission of this opinion may have operated to prevent attention to them, the case is not so with Clouds.

Luke Howard, from "Essay on the Classification of Clouds"