zany (n.) comic performer, 1580s, from French zani, from Italian zani, zanni "a zany, clown," originally Zanni, Venetian dialect variant of Gianni, pet form of Giovanni "John;" thus equivalent to English Jack.

The earliest known use of the word zany is in the late 1500s. OED's earliest evidence for zany is from 1596, in the writing of Thomas Lodge, author and physician. zany is a borrowing from French. It is derived from French zani and Italian zani.

Etymology [ edit] From Middle French zani, zanni, from Italian zanni (“a kind of masked clown character”), from Zanni, a dialectal form of Giovanni.

Zanni comes from a dialect nickname for Giovanni, the Italian form of John. The character quickly spread throughout European theater circles, inspiring such familiar characters as Pierrot and Harlequin, and by the late 1500s an anglicized version of the noun zany was introduced to English.