Upset then abuse Highlanders (9)

I believe the answer is:

bhutanese

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'upset then abuse highlanders' is the definition.
Although both the answer and definition are adjectives, I don't see how one could define the other.

'upset then abuse' is the wordplay.
'upset' indicates an anagram.
'then'+'abuse'='thenabuse'
'thenabuse' with letters rearranged gives 'BHUTANESE'.

Can you help me to learn more?

(Other definitions for bhutanese that I've seen before include "Particular Himalayan" , "People used to high living" .)

I've seen this clue in The Times.

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