QUIXOTIC

adj. idealistic, impractical, impracticable, unrealistic, unrealizable, visionary, romantic, fantastic, chimerical, fanciful, dreamlike, dreamy, nephelococcygeal, starry-eyed, optimistic, rash, absurd, mad, foolhardy, reckless, wild, preposterous, ridiculous When he was young, he had a quixotic notion that he could improve the world