Means "nerve". "If I Only Had the Noive" is a quote from "The Wizard of Oz" (1939 film) sung by the lion.
The actors natural regional accent was exploited and emphasized for comic effect in this song, which includes several words that are pronounced in a stereotypically "Brooklynese" way: "voive" for "verve", "desoive" for "deserve", and "noive" for "nerve".
Used in Internet Forums to describe or to exaggerate the assurance of a poster.