Take no notice of Italian gentleman losing head (6)
I believe the answer is:
ignore
'take no notice of' is the definition.
(I've seen this before)
'italian gentleman losing head' is the wordplay.
'italian gentleman' becomes 'signore'.
'losing head' means to remove the first letter.
'signore' with its first letter taken away is 'IGNORE'.
(Other definitions for ignore that I've seen before include "Spurn" , "Deliberately take no notice" , "bypass" , "Pay no attention to, disregard" , "Intentionally disregard" .)