Mswapheni

A person, usually a blesser or sugar mama who just swipes his/her card without any hesitation.

We are out of beer... mswapheni
We are out of meat... mswapheni

Madiba

A Xhosa clan name that was made famous by former president Nelson Mandela.

Madiba passed away in December 2013.

Molweni

A Xhosa greeting used to greet multiple people. You use molo to greet one person.

Molweni bantu abadala.

Molo

A Xhosa greeting used to greet one person. To greet multiple people, you say molweni.
Some people spell it as mholo.

"Molo sisi, kunjani? Uphilile na? Bendicel'umzuzu wokuthetha nawe mna" - Mandisi Dyantyis

Marete

A baSotho/Tswana term for Balls (As in testicles, not a soccer ball).

O boa marete saan

Matric

The last year of high school (grade 12).

I can't wait to do my matric.

Matric Dance

Also known as Matric Farewell - Is when grade 12 (last year of high school) learners have one final formal function, often followed by parties, underage drinking and bad decisions. Each school usually has its own dance and pupils usually come with a date and wear expensive suits and dresses.
Americans would call it prom

I don't know who I am going to take to the Matric Dance.

Mahala

A Zulu term that means for nothing. Free; obtained without payment or difficulty. It is however not only used by Zulu, it has been incorporated to modern South African lingo.

Buy 1 drink and get the second one mahala.

Mntkbw

Xhosa term derived from Mntakabawo which directly translates to "My dad's child". This term doesn't necessarily refer to someone you are related to. It can be used to refer to a friend or any random person.

I'm so tired mntkbw.

Moer

To beat someone to a pulp.

Can also be a swear word in Afrikaans

I will moer you.