ZANY, a fool or silly person. The word came into English in the 16th century from Ital. Zane, mod. Zanni, an abbreviation of the name Giovanni (John). This familiar form of the name was given by Italians to a special type of clown or buffoon who acted as an attendant or follower of the regular professional clown on the stage and made clumsy and ludicrous attempts to mimic his performance.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)