It's a common word in almost all African langauges (Afrikaans, Xhosa, Tswana, Sotho, Zulu etc.) throughout Southern Africa (South Africa, Namibia, Botswana, Zambia, Zimbabawe, Mozambique, Lesotho & Swaziland) for anything that you can smoke (Marijuana, tabbacco etc.).
Afrikaans: Jy! Gooi my vinnig 'n light. Ekke wil 'n bietjie TWAK rook.
Translated in English: Can you lend me a lighter, I want to smoke some tabbacco.