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1.
South African slang used by all ethnic groups. An appeal to reason, often ironic or sarcastic.

Interjection composed of "hau" - indicating surprise - and "marra", an Africanisation of the Afrikaans "maar", meaning "but". Often followed by "wena" or "uena", the emphatic/ accusative/ inclusive of the second person singular.
Hau marra, Sir, you are giving us too much homework these days!
by Polly Glot December 07, 2010