An overage criminal, usually (2,7)
I believe the answer is:
on average
'usually' is the definition.
(I've seen this before)
'an overage criminal' is the wordplay.
'criminal' indicates anagramming the letters.
'an'+'overage'='anoverage'
'anoverage' is an anagram of 'ON AVERAGE'.
(Other definitions for on average that I've seen before include "typically speaking" , "Usually" , "Generally" .)