Crossword Genius

Now their work became less acceptable (4,4)

Ross

I believe the answer is:

wore thin

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'less acceptable' is the definition.
I can't judge whether this defines the answer.

'now their work' is the wordplay.
'work' indicates anagramming the letters.
'now'+'their'='nowtheir'
'nowtheir' is an anagram of 'WORE THIN'.

'became' is the link.

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I've seen this clue in The Guardian.
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