When spoken endlessly, very Italian (5)
I believe the answer is:
assai
'very italian' is the definition.
('very' in Italian)
'when spoken endlessly' is the wordplay.
'when' becomes 'as' (eg 'when I walked' means 'as I walked').
'spoken' becomes 'said' (said out loud).
'endlessly' means to remove the last letter.
'said' with its final letter taken away is 'sai'.
'as'+'sai'='ASSAI'
(Other definitions for assai that I've seen before include ""Very" as musical instruction" , "attack in concert, for the most part" , "small, purple, nutritional fruit" , "Italian greatly contributed to score" , "Musician's very" .)