is a specific kind of: comedian, comic.

is a broader term that covers: harlequin | fool, jester, motley fool | whiteface | zany.

instances of which are: Emmett Kelly, Kelly, Weary Willie.

derivation: antic, clown, clown around | blunder, boob, drop the ball, goof, sin | goofy, silly, wacky, whacky, zany.