Zulus, one crossing briefly Orange River (7)

I believe the answer is:

zambezi

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'river' is the definition.
(Zambezi River is an example)

I don't understand how the rest of the clue works.

(Other definitions for zambezi that I've seen before include "River of southeast Africa" , "Maze biz (anag.); African river" , "River rising in Zambia" , "Fourth longest African river" , "River flowing into Indian Ocean northeast of Beira in Mozambique" .)

I've seen this clue in The Times.

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