To start with, be embarrassed by the early enthusiasm (5,5)

I believe the answer is:

first flush

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'early enthusiasm' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.

'to start with be embarrassed by' is the wordplay.
'to start' becomes 'first' (synonyms).
'with' means one lot of letters go next to another.
'be embarrassed by' becomes 'flush' (I can't explain this - if you can you should believe this answer much more).
'first'+'flush'='FIRST FLUSH'

'the' is the link.

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I've seen this clue in the Evening Standard.

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