Late reaching conclusion where no progress is possible (7)

I believe the answer is:

deadend

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'where no progress is possible' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.

'late reaching conclusion' is the wordplay.
'late' becomes 'dead' (similar in meaning).
'reaching' is a charade indicator (letters next to each other).
'conclusion' becomes 'end' (something's conclusion is its end).
'dead'+'end'='DEADEND'

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I've seen this clue in The Daily Express.

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