Swift runner, zebra left eagle confused (7)

I believe the answer is:

gazelle

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'swift runner' is the definition.
(I've seen this in another clue)

I don't understand the remainder of the clue.

(Other definitions for gazelle that I've seen before include "Small graceful antelope" , "Slender antelope" , "Large-eyed antelope" , "Graceful beast" , "''both / beautiful, one a ...'' (Yeats)" .)

I've seen this clue in The Sun.

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