Green’s Dictionary of Slang

(US) gaiety, liveliness.

1942		Berrey & Van den Bark Amer. Thes. Sl.
1970		Gourmet Jan. 18/2: No party got into full swing until Tallulah arrived to put her particular type of zizz into it [OED].
1983		Times 22 Feb. 12/6: The Queensgate centre lacks, perhaps, finesse and a touch of zizz.
2000		Guardian 28 Mar. 22: Gilbert and Sullivan’s career is delightful. (If you have a little zizz).