Proprietor's depressing experience missing daughter (5)
I believe the answer is:
owner
'proprietor's' is the definition.
('owner' can be a synonym of 'proprietor')
'depressing experience missing daughter' is the wordplay.
'depressing experience' becomes 'downer' (I've seen this before).
'missing' is a deletion indicator.
'daughter' becomes 'd'.
'downer' with 'd' taken away is 'OWNER'.
(Other definitions for owner that I've seen before include "landlord" , "possessive type" , "Possessor, proprietor" , "Legal possessor" , "Keeper" .)