Yat, n. — Green’s Dictionary of Slang

Yat n.

[the locally common greeting, ‘Where y’at?’ i.e. ‘How are you?’, used of health, economic security, etc )]

(US) a New Orleans native, usu. working-class.

2017		T. Pluck Bad Boy Boogie [ebook] That New Orleans ‘Yat’ accent which resembled the Bronx more than a Southern lilt.
2020		D. Winslow ‘Broken’ in Broken 3: Wilmer’s a New Orleans guy, as much a Yat as the rest of them [ibid.] 29: ‘We’re just Yats [...] New Orleans white trash’.