Broken promise working occasionally? (4-3)

I believe the answer is:

semi-pro

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'working occasionally?' is the definition.
I don't know anything about this answer so I can't judge whether this works.

'broken promise' is the wordplay.
'broken' indicates anagramming the letters.
'promise' is an anagram of 'SEMI-PRO'.

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I've seen this clue in The Telegraph.

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