Be very good or excellent but not fast (5)

I believe the answer is:

excel

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'be very good or' is the definition.
I can't judge whether this definition defines the answer.

'excellent but not fast' is the wordplay.
'but not' suggests deleting specific letters.
'fast' becomes 'lent' (Lent is a period of fasting in Christianity).
'excellent' with 'lent' taken away is 'EXCEL'.

Can you help me to learn more?

(Other definitions for excel that I've seen before include "Outrival" , "Be exceptionally good (at something)" , "Do brilliantly" , "well above average" , "Do exceedingly well" .)

I've seen this clue in The Daily Express.

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