tilt at windmills

Etymology
From a passage in the novel Don Quixote where the eponymous character tilts (i.e. jousts) at windmills that he has mistaken for giants.

Verb

 * 1)  To attack imaginary enemies.
 * 2)  To go on a wild-goose chase; to persistently engage in a futile activity.

Translations

 * Catalan: lluïtar contra molins de vent
 * Finnish: taistella tuulimyllyjä vastaan
 * French:
 * German:
 * Hebrew:
 * Irish: dul i ngleic le samhailtí
 * Norwegian:
 * Bokmål:, kjempe mot vindmøller
 * Polish:
 * Russian: боро́ться с ветряны́ми ме́льницами,
 * Spanish: luchar contra molinos de viento
 * Swedish: slåss mot väderkvarnar
 * Welsh: ymladd â melinau gwynt