clown (n.) Look up clown at Dictionary.com
1560s, also cloyne, "rustic, boor, peasant," origin uncertain. Perhaps from Scandinavian dialect (cf. Icelandic klunni "clumsy, boorish fellow;" Swedish kluns "a hard knob, a clumsy fellow"), or akin to North Frisian klönne "clumsy person," or, less likely, from Latin colonus "colonist, farmer." Meaning "fool, jester" is c.1600. "The pantomime clown represents a blend of the Shakes[pearean] rustic with one of the stock types of the It. comedy" [Weekley]. Meaning "contemptible person" is from 1920s.
clown (v.) Look up clown at Dictionary.com
c.1600, from clown (n.); colloquial sense of "to behave inappropriately" (e.g. clown around, 1932) attested by 1928, perhaps originally in music performance slang. Related: Clowned; clowning.