The gaffer's an enthusiast about Rome, possibly (7)
I believe the answer is:
foreman
'the gaffer's' is the definition.
('foreman' can be a synonym of 'gaffer')
'enthusiast about rome possibly' is the wordplay.
'enthusiast' becomes 'fan' (fan is a kind of enthusiast).
'about' is an insertion indicator.
'possibly' is an anagram indicator.
'rome' anagrammed gives 'orem'.
'fan' going around 'orem' is 'FOREMAN'.
'an' is the link.
(Other definitions for foreman that I've seen before include "Gaffer, overseer" , "Gaffer, boss" , "Fellow in charge" , "Supervising worker" , "Charge hand" .)