The lift is out of order, being most dirty (9)

I believe the answer is:

filthiest

'most dirty' is the definition.
('filthy' can be a synonym of 'dirty')

'the lift is out of order' is the wordplay.
'out of order' indicates an anagram.
'the'+'lift'+'is'='theliftis'
'theliftis' with letters rearranged gives 'FILTHIEST'.

'being' is the link.

I've seen this clue in The Guardian.

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