k.b., n.² — Green’s Dictionary of Slang

k.b. n.²

[abbr.; the initials are preferred to the offensive term kaffir beer under kaffir adj.]

(S.Afr.) kaffir beer (a form of beer brewed with malted sorghum millet).

1962		Casey ‘Kid’ Motsisi in Casey and Co. (1978) 47: He [...] made a compromise — to drink only K.B., including the other homemade concoctions which are calculated to make you Nagasaky only after putting as little as a jam tin’s amount under your belt.
1970		H. Kuper Witch in my Heart III i: Here’s a bob. Give us KB.
1980		S. Sepamla Forced Landing n.p.: For the K.B. drinkers in the lounge there were wooden benches.