Medal welcoming Italy's departure (5)
I believe the answer is:
going
'departure' is the definition.
(I've seen this before)
'medal welcoming italy's' is the wordplay.
'medal' becomes 'gong' (I've seen this before).
'welcoming' means one lot of letters goes inside another (in sense of 'inviting in').
'italy' becomes 'i'.
'gong' going around 'i' is 'GOING'.
(Other definitions for going that I've seen before include "Running; leaving" , "Departure; current (rate)" , "Available" , "factor in horse's performance?" , "Failing to stay" .)