Over an hour spot does, very old (4)

I believe the answer is:

doth

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'does very old' is the definition.
I can't tell whether this defines the answer.

'over an hour spot' is the wordplay.
'over' says to put letters next to each other.
'an hour' becomes 'h'.
'spot' becomes 'dot' (I've seen this before).
'h' after 'dot' is 'DOTH'.

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I've seen this clue in The Times.

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