Green’s Dictionary of Slang

(US) New Orleans.

1938		J. Morton letter 27 Apr. in Reich & Gaines Jelly’s Blues (2003) 38: These [pianists] set a pace for everyone [who] entered N.O. I have never known anyone to leave N.O. victorious.
1965		G. Melly Owning Up (1974) 46: The N.O. fanatics called Ken ‘The Guvnor’.
1992		B. Gifford Night People 163: Daddy called tonight from N.O.