Shun topless Italian man (6)
I believe the answer is:
ignore
'shun' is the definition.
'topless italian man' is the wordplay.
'topless' means to remove the first letter.
'italian man' becomes 'signore' (Italian equivalent to mister).
'signore' with its initial letter taken away is 'IGNORE'.
(Other definitions for ignore that I've seen before include "Pay no heed to" , "Spurn" , "Pass over" , "Fail to observe" , "Refuse to notice or acknowledge" .)