Not loveless, indeed, but depressed (6)
I believe the answer is:
dented
'depressed' is the definition.
(thesaurus)
'not loveless indeed' is the wordplay.
I cannot really understand how this works, but
'not' could be 'nt' (synonyms) and 'nt' is located in the answer.
The remaining letters 'deed' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'but' is the link.
Can you help me to learn more?
(Other definitions for dented that I've seen before include "Dinged" , "Tended to be depresed" , "made an impression" , "Made depression in through pressure or impact" , "Bashed in" .)