Refractory unit's turn to separate army medic and American (8)

I believe the answer is:

mutinous

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'refractory' is the definition.
(thesaurus)

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

(Other definitions for mutinous that I've seen before include "Rebellious like the Bounty's crew" , "Insurgent" , "Insubordinate" , "bolshie" , "Unsubmissive" .)

I've seen this clue in the Sydney Morning Herald.

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