The English word quixotic means impractically idealistic, especially in a romantically lofty or unrealistic way.
The adjective comes from Don Quixote, Cervantes’ protagonist, whose idealized vision of chivalry repeatedly collides with ordinary reality. Quixote sees himself as a knight-errant defending the helpless, but his actions often produce confusion, embarrassment, or danger because he mistakes commonplace objects and events for elements of heroic romance.
English uses quixotic both critically and sympathetically. It can describe a foolishly impractical enterprise, but it may also suggest admirable courage, generosity, or devotion to an ideal despite poor chances of success. The related noun quixotism refers to impractical idealism or extravagant chivalric action. The expression “tilting at windmills,” also derived from the novel, similarly describes attacking imagined enemies or pursuing a misguided heroic cause.