Fearless loved one, disheartened (6)
I believe the answer is:
daring
'fearless' is the definition.
(thesaurus)
'loved one disheartened' is the wordplay.
'loved one' becomes 'darling' (I've seen this before).
'disheartened' says to hollow out the word (remove centre letters).
'darling' with its centre taken out is 'DARING'.
(Other definitions for daring that I've seen before include "Boldness" , "Courageous" , "A grind (anag.)" , "Adventurous or audaciously bold" , "Boldly dramatic or unconventional" .)