clown

Short definition from Wiktionary

Noun

1. 1
   A slapstick performance artist often associated with a circus and usually characterized by bright, oversized clothing, a red nose, face paint, and a brightly colored wig.
2. 2
   A person who acts in a silly fashion.
3. 3
   A stupid person.
4. 4
   A man of coarse nature and manners; an awkward fellow; an illbred person; a boor.
5. 5
   One who works upon the soil; a rustic; a churl; a yokel.
6. 6
   A clownfish.

Verb

1. 1
   To act in a silly or playful fashion.
2. 2
   To ridicule, make fun of.