Take no notice of Italian gentleman failing to start (6)
I believe the answer is:
ignore
'take no notice of' is the definition.
(I've seen this before)
'italian gentleman failing to start' is the wordplay.
'italian gentleman' becomes 'signore'.
'failing to start' means to remove the first letter.
'signore' with its first letter taken off is 'IGNORE'.
(Other definitions for ignore that I've seen before include "'Disregard, overlook (6)'" , "Cut head off" , "set aside" , "Deliberately disregard" , "Pay no attention to, disregard" .)