pizazz n.

also pizzaz; pizzazz, a vogue word from 1937 in the current sense of (more or less) "energetic and exciting quality," probably originally college or show-biz slang.

Pizazz, to quote the editor of the Harvard Lampoon, is an indefinable dynamic quality, the je ne sais quoi of function; as for instance, adding Scotch puts pizazz into a drink. Certain clothes have it, too. [Harper's Bazaar, March 1937]

There is an earlier use, with an uncertain (but seemingly negative) sense, in a satirical Chicago Journal newspaper piece written in supposed current slang in 1912 ["Nix on the Rough Stuff: Chicago's Clean Language League Throws the Kibosh Into Low-Brow Lingo"]:

Brother Russel declared, bo, that his crowd had already framed it up with some of the big guys in the music world to put the kibosh on this line of junk, and that it was only a question of time before they would have such pieces as "When I Get You Alone Tonight" completely on the pizzazz.