House officer in an Italian city (4)
I believe the answer is:
como
'italian city' is the definition.
The definition suggests a singular noun which matches the answer.
'house officer in' is the wordplay.
'house' becomes 'om' (I can't justify this - if you can you should believe this answer much more).
'officer' becomes 'co' (Commanding Officer abbreviation).
'in' indicates putting letters inside.
'om' put into 'co' is 'COMO'.
'an' acts as a link.
Can you help me to learn more?
(Other definitions for como that I've seen before include "Town and lake in north Italy" , "North Italian lake" , "Italian city and lake" , "lake resort" , "Not Italy's biggest lake" .)