Italian poet’s heartless noble (6)
I believe the answer is:
aristo
'noble' is the definition.
(I've seen this before)
'italian poet's heartless' is the wordplay.
'italian poet' becomes 'ariosto' (Ludovico Ariosto).
'heartless' says to hollow out the word (remove centre letters).
'ariosto' with its centre removed is 'ARISTO'.
(Other definitions for aristo that I've seen before include "Owned by the state" , "High-hat" , "privileged individual" , "one of the best" , "Member of the nobility (abbr)" .)