Outlaw group, Italian (6)
I believe the answer is:
bandit
'outlaw' is the definition.
(I know that bandit is a type of thief)
'group italian' is the wordplay.
'group' becomes 'band' (band can mean a group of people).
'italian' becomes 'it' (abbreviation for Italian).
'band'+'it'='BANDIT'
(Other definitions for bandit that I've seen before include "Armed brigand" , "Violent outlaw" , "Enemy aircraft" , "Marauder" , "Armed robber in the Wild West" .)