The Italian leaves sweetheart out in the city (5)
I believe the answer is:
lagos
'the city' is the definition.
(Lagos is an example)
'the italian leaves sweetheart out' is the wordplay.
I cannot really understand how this works, but
'the italian' could be 'la' ('the' in Italian) and 'la' is located in the answer.
This explanation may well be incorrect...
'in' acts as a link.
Can you help me to learn more?
(Other definitions for lagos that I've seen before include "Largest city and once capital of Nigeria" , "African port" , "Formerly capital of Nigeria" , "Strange goals of the Nigerian port" , "African city" .)