Noblemen in pubs carrying on (6)
I believe the answer is:
barons
'noblemen' is the definition.
(baron is a kind of nobleman)
'pubs carrying on' is the wordplay.
'pubs' becomes 'bars' (a bar is a pub).
'carrying' is an insertion indicator.
'bars' enclosing 'on' is 'BARONS'.
'in' is the link.
(Other definitions for barons that I've seen before include "Lords" , "No bars for the British peers" , "Low-ranking British peers" .)