Green’s Dictionary of Slang

(S.Afr.) a police informer.

1969		M. Benson At Still Point (1971) 157: Impimpis! Informers! What have they done to my people!
1987		M. Melamu Children of Twilight 153: The ‘mpimpi’ is hinty. They say the ‘Duke’ got him at last .
1989		C.J. Fourie Big Boys in Kani (1994) 131: daniel: Who do you necklace? solomon: Impimpi.
1990		R. Malan My Traitor’s Heart (1991) 209: It freed the old man from the stigma of being an impimpi, one who betrays secrets to whites.
2000		A. Brink Rights of Desire (2001) 202: Impimpi they called me. That’s what the black people mos call someone who goes to the pollies.
2000		I. van Kessel Beyond our Wildest Dreams 127: The practice of burning social enemies had spread [...] now taking the gruesome form of necklacing the ‘impimpis’ (suspected informers).
2011		Mail & Guardian (Johannesburg) 5 May 🌐 Impimpi. A fink.