Lazzi (/ˈl[unsupported input]t[unsupported input]si/; from the Italian lazzo, a joke or witticism) is an improvised comic dialogue or action commonly used in the Commedia dell'arte. Most English-speaking troupes use the Italian plural "lazzi" as the singular and "lazzis" for the plural.
During improvised performances a lazzi may be used to fill time or to ensure a certain frequency of laughs in a show. For practical purposes a lazzi may be any bit of business that may be easily recalled and performed in another situation, somewhat like a catch phrase. In any given troupe, the senior player could have well over one hundred lazzis at his/her disposal. The performer would not only have these well rehearsed but would also pass them on to future generations within the troupe. As soon as a lazzi is initiated by one player, all of the other players must fall in, thus performing a lazzi requires every member of the troupe to know the routine as well as great teamwork. In Commedia dell'arte, the Harlequin or Zanni would most likely have these lazzis at their disposal. Also, lazzis' movements are normally very exaggerated.