As an honorary adopted South African, I will share some of that English.
Biltong - a dried meat like beef jerky, could be made of ostrich or other meat though
biscuit - a cookie
boerewors - a sausage, like a bratwurst.
braai - bbq, a good place to enjoy those boerewors and other goodeis like pork rashers
bunny chow - not green rabbit food, no! it is curry served in a hollowed-out half-loaf of bread
eish - Used to express surprise, wonder, frustration or outrage: "Eish! That cut was eina!"
howzit - A traditional South African greeting that translates roughly as "How are you?", "How are things?" or simply "Hello".
just now - If a South African tells you they will do something "just now", they mean they'll do it in the near future - not immediately: "I'll do the dishes just now." I had a lot of fun with this concept
lekker - Nice, good, great, cool or tasty.
now-now - Shortly, in a bit: "I'll be there now-now." See also "just now"
pavement - South Africans walk on pavements and drive cars on the road (at least that's the idea). The pavement is the sidewalk.
robot - not R2D2. a traffic light.
sarmie - Sandwich.
takkies - Running shoes or sneakers.
ubuntu - Southern African humanist philosophy that holds as its central tenet that a person is a person through other persons.
yebo - yes, as in agreement
With gratitude to LouBelle for her patiently teaching me this dialect.