Grumble about the main course, maybe (4)

I believe the answer is:

beef

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'grumble' is the definition.
(both can mean to complain)

I cannot understand how the rest of the clue works.

(Other definitions for beef that I've seen before include "joint, perhaps" , "Brawn; complaint" , "Complain; meat" , "See 24" , "Meat of the cow" .)

I've seen this clue in The Irish Independent.

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