Don Quix·ote /ˌdɒn ˈkwɪksət,-kɪˈhəʊti $ ˌdɑːn-, -ˈhoʊti/ noun
someone who is determined to change what is wrong, but who does it in a way that is silly or not practical. This name comes from the main character in the humorous book Don Quixote de la Mancha by Miguel de Cervantes. Don Quixote wants to be a knight like the characters he admires in old stories, but when he tries to copy their adventures and behaviour, he makes many stupid mistakes.

[TahlilGaran] Dictionary of Contemporary English ▲