Golfing or boxing circles? (6)

I believe the answer is:

rounds

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'circles?' is the definition.
('round' can be a synonym of 'circle')

I cannot understand how the remainder of the clue works.

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(Other definitions for rounds that I've seen before include "periods of fighting" , "Skirts" , "Series of recurring actions or events" , "Circles" , "Circuits of the golf course" .)

I've seen this clue in The Globe and Mail and The Guardian.

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