Green’s Dictionary of Slang

(orig. US Und.) an alias, a false name.

1985		G. Petievich Quality of the Informant 152: Her name is [...] Rosanna DuMaurier. Her aka is Rosemary Cramp.
1989		C. Hiaasen Skin Tight 190: Under AKAs, the police bulletin listed one: Chemo.
1991		J. Wambaugh Blue mirage 185: They also think his aka is for real.
2002		S. Russell Lethal Intent 293: Because [Aileen] Wuornos seemed to use her aka’s with confidence, it was possible she was using them with permission.
2012		G. Pelecanos (con. 1972) What It Was 38: The rap sheet description included known a.k.a.’s.