Credit myself with one felony (5)
I believe the answer is:
crime
'felony' is the definition.
(I've seen this in another clue)
'credit myself with one' is the wordplay.
'credit' becomes 'cr' (abbreviation).
'myself' becomes 'I'.
'with' is a charade indicator (letters next to each other).
'one' becomes 'me' (a setter might use 'one' to humourously mean 'me').
'cr'+'i'+'me'='CRIME'
(Other definitions for crime that I've seen before include "wrong-doing" , "Wicked deed" , "Dangerous driving perhaps" , "Transgression of the law" , "Murder, perhaps" .)