I may be an old Italian figure (5,7)
I believe the answer is:
roman numeral
'i' is the definition.
(I is the Roman numeral for one)
'an old italian figure' is the wordplay.
'an old italian' becomes 'roman' (I've seen this before).
'figure' becomes 'numeral' (I've seen this before).
'roman'+'numeral'='ROMAN NUMERAL'
'may be' is the link.
(Other definitions for roman numeral that I've seen before include "Eg, X or V or M" , "I for one!" , "I say" , "Such as V, X or L" , "I, perhaps" .)