Zany

Zany has a very interesting background. As a noun, it is defined as "a comic performer who assists or imitates a clown, acrobat, or mountebank" or "a comical person given to extravagant or outlandish behavior" (The American Heritage College Dictionary, 4th ed., p 1592). However, its popular usage is as an adjective that attributes the noun as something clownish or "comical because of incongruity or strangeness" (loc. cit.)
According to the American Heritage College Dictionary, zany entered English through the French word "zani," which came from the a regional dialect of Italian's "zanni." The interesting part is that "Zanni" is a variation of the Italian word "Gianni," which means John. John was a character in the Italian comedy: commedia dell'arte. This was a traveling troupe of ten people (eight men and two women), who performed improvisational theatre from the 16th century to the 18th century. Their skits were about adultry, jealousy, love, and old age. They used routines and props to play out either small skits, burle (jokes), or improv. dialogue. Out of these troupes we get the precursers of clowns: the Zanni and the Harlequin (Wikipedia)

The picture is from Wikiepdia. It was done by Karel Dujardins, and it shows one such commedia dell'arte troupe.