Zany

noun
a buffoon in one of the old comedies; imitates others for ludicrous effect
noun
a man who is a stupid incompetent fool
Similar: fathead, goof, goofball, bozo, jackass, goose
adjective
ludicrous, foolish
“gave me a cockamamie reason for not going”
Similar: cockamamie, cockamamy, goofy, sappy, silly, wacky
adjective
like a clown
“a buffoonish walk”
Similar: buffoonish, clownish, clownlike