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bergie - from berg, mountain, originally referring to vagrants who sheltered in the forests of Table Mountain; now a mainstream word for a particular subculture of vagrants in Cape Town. When used as slang refers to anyone down and out
bioscope, bio - cinema, movie theatre (now dated), originally a defunct international English word it has survived longer in South Africa as a result of the influence of the Afrikaans cognate bioskoop
boerewors - spicy sausage (Afrikaans) farmer-sausage, used as a mainstream word in South African English
bru - male friend (shortening of broer meaning brother, see also bra below)
dinges - thingamabob, a wotzit or a whatchamacallit
dof - stupid
fyndraai - at the brink of orgasm (Afrikaans - at the fine end of the last turn)
gatvol - fed up, had enough. (Afrikaans - hole-full)
goof, goef - swim, dip
hoesit, hoezit, howzit - how’s it going? How are you?
jislaaik! - wow!
kiff, kif, kief - (adjective) cool, neat, great, wonderful (from Arabic, kayf, meaning enjoyment or wellbeing)
windgat - highty-tighty; highty and mighty; snobbish. (Afrikaans: wind hole)
vrot - rotten, putrid
stukkend - (Afrikaans) broken
swak - broke. Original Afrikaans: weak. "I'm swak, ek sê". Also used to express disgust or derision (depending on tone and context), for example: "It's swak that I failed the test"
Check out the full Wikipedia list.