Synonyms for Zany (same or very similar meaning)
WordNet sense 1 (a man who is a stupid incompetent fool):
bozo, cuckoo, fathead, goof, goofball, goose, jackassWordNet sense 2 (ludicrous, foolish):
cockamamie, goofy, sappy, silly, wacky, cockamamy, whackyWordNet sense 3 (devoid of good sense or judgment):
foolishWordNet sense 4 (like a clown):
buffoonish, clownish, clownlikeWordNet sense 5 (full of or characterized by humor):
humorous, humourousFrom the ODE community, based on WordNetadd/edit