Green’s Dictionary of Slang

kaffir n.

also caffre, kaffer, kafir
[Arab kefir, an infidel; orig. a Xhosa-speaking African and by extension, any African; orig. (mid-15C) seen as a simple description of a given ethnic group, the term became insulting and abusive and its use is now actionable]
(orig. S.Afr.)

1. [mid-19C+] a derog. term for a black person.

2. [mid-19C–1900s] a pimp, an unpleasant person.

3. [1900s] a generic name for any indigenous language spoken in S. Africa.

4. [late 19C-1900s] an insult, irrespective of race.

In compounds

Kaffirland (n.) (also Cafferland, Caffreland, Kafirland)

[mid-19C] the Cape provinces; latterly South Africa.

kaffir-lover (n.)

[2010s] (S.Afr.) one who is deemed (by racists) to to be overly friendly to blacks.

kaffir’s tightener (n.) [tightener n.; such a meal supposedly satisfies even an African]

[mid-19C] (S.Afr.) a large, heavy meal.

In phrases

go to the kaffirs (v.) [derog. var. on SE colloq. phr. go to the dogs]

[1950s+] to deteriorate, to decline socially .

Jack Kaffir (n.)

[late 19C] a generic term for black people.

kitchen kaffir (n.)

[1980s+] pidgin Zulu language.

white kaffir (n.)

1. [mid-19C+] a derog. term for a white perceived as behaving badly by their peers.

2. [mid-19C+] a white who has become overly close to or assimilated into the black community.

3. [1930s+] an albino.