Prohibit one including Italian singer (8)
I believe the answer is:
baritone
'singer' is the definition.
(baritone is a kind of singer)
'prohibit one including italian' is the wordplay.
'prohibit' becomes 'bar' (barring is a kind of prohibiting).
'including' indicates putting letters inside.
'italian' becomes 'it'.
'bar'+'one'='barone'
'barone' placed around 'it' is 'BARITONE'.
(Other definitions for baritone that I've seen before include "Male singer between tenor and bass" , "solo voice" , "Adult male singing voice" , "Male singer in boater, strangely" , "One who can sing" .)