Actors marry dons around Highland county (4,3,8)

I believe the answer is:

ross and cromarty

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'highland county' is the definition.
The definition suggests a singular noun which matches the answer.

'actors marry dons around' is the wordplay.
'around' indicates anagramming the letters.
'actors'+'marry'+'dons'='actorsmarrydons'
'actorsmarrydons' anagrammed gives 'ROSS AND CROMARTY'.

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(Another definition for ross and cromarty that I've seen is " Old county".)

I've seen this clue in The Guardian.

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