Green’s Dictionary of Slang

1. (US) of black or minority activists, to harass the white establishment for their community’s gain, esp. by taking advantage of liberal guilt.

[1967		Ragni & Rado ‘Colored Spade’ 🎵 I’m a / Colored spade / A nigger / A black nigger / A jungle bunny / Jigaboo coon / Pickaninny mau mau].
1971		Harper’s Mag. June 9: The English Department of Columbia University had been mau-maued by that termagant of Women’s Lib.
1972		E. Grogan Ringolevio 446: Some paper cats running around, trying to mau-mau some loose change from the bearded, white, liberal merchants.
1981		H. Gould Fort Apache, The Bronx 140: He kept staring at the guy [...] Nobody was going to mau mau him.
2000		N. Griffiths Grits 466: He cawls it, arfta some sixties Black Poer fing, ‘Mau-Mauing’; I cawl it acting tha cunt.

2. (US Und.) to murder to assassinate.

2003

Simon & Pelecanos ‘Bad Dreams’ Wire ser. 2 ep. 11 [TV script] ‘They did mau-mau Willis.’ ‘Why did they kill him?’.