Fighting a case (6)

I believe the answer is:

action

I believe this is a double definition.

'fighting' is the first definition.
(thesaurus)

'a case' is the second definition.
('action' can be a synonym of 'case')

(Other definitions for action that I've seen before include "Lawsuit; something done" , "Court case" , "Not CIA (anag)" , "The mechanism of, say, a watch" , "Fighting - lawsuit" .)

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

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