Deviation of just one percent - basically, there's nothing wrong with it (10)
I believe the answer is:
perfection
'wrong with it' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Maybe you can see a link between them that I don't see?
'deviation of just one percent basically there's nothing' is the wordplay.
I cannot really understand how this works, but
'of' could be 'o' and 'o' is found in the answer.
'one' could be 'i' (Roman numeral) and 'i' is found in the answer.
'there's' could be 'n' (I've seen this in other clues) and 'n' is found in the answer.
The remaining letters 'perfect' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for perfection that I've seen before include "Highest state" , "Faultlessness" .)