Offence, capital, here in Egypt (5)
I believe the answer is:
sinai
'here in egypt' is the definition.
(I know that Sinai is in Egypt)
'offence capital' is the wordplay.
'offence' becomes 'sin' (a sin is an offence or transgression).
'capital' becomes 'ai' (resembles 'A1', old-fashioned term for excellent).
'sin'+'ai'='SINAI'
(Other definitions for sinai that I've seen before include "Mountain source of Mosaic Law" , "Peninsula, mostly desert, at north end of Red Sea" , "Mountainous Egyptian peninsula" , "place to receive instructions about behaviour" , "Deserted area" .)