The Italian's stopping doctor's tipple (4)
I believe the answer is:
mild
'tipple' is the definition.
(mild is a type of drink)
'the italian's stopping doctor's' is the wordplay.
'the italian' becomes 'il' ('the' in Italian).
'stopping' is an insertion indicator (stopping can mean blocking a gap).
'doctor' becomes 'md' (synonyms).
'il' placed into 'md' is 'MILD'.
(Other definitions for mild that I've seen before include "Balmy or moderate" , "Moderate, temperate" , "having little effect" , "Gentle and moderate" , "Far from extreme" .)