Connected gangster fibbed (6)
I believe the answer is:
allied
'connected' is the definition.
(allied can mean connected or associated)
'gangster fibbed' is the wordplay.
'gangster' becomes 'al' (Al Capone).
'fibbed' becomes 'lied' (fib can mean to tell a lie).
'al'+'lied'='ALLIED'
(Other definitions for allied that I've seen before include "Joined in friendship, treaty, etc" , "Joined together for a purpose" , "Connected, related" , "Joined to, combined with" , "Joined together for mutual support" .)