An orderly area of the UK (6)

I believe the answer is:

antrim

'area of the uk' is the definition.
(county of Northern Ireland)

'an orderly' is the wordplay.
'orderly' becomes 'trim' (synonyms).
'an'+'trim'='ANTRIM'

(Other definitions for antrim that I've seen before include "NI county" , "Giant's Causeway county" , "Ulster county" , "NI town" , "town in Ireland" .)

I've seen this clue in The Guardian.

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