Is it ensure, insure, or assure?
1852, from Italian scherzo, literally "sport, joke," from scherzare "to jest or joke," from a Germanic source (cf. Middle High German scherzen "to jump merrily, enjoy oneself," German scherz "sport"), from PIE *(s)ker- (2) "leap, jump about." The lively second or third movement in a multi-movement work. Scherzando is the Italian gerund of scherzare.