Experienced quite a lot of remorse, as one does (8)
I believe the answer is:
seasoned
'experienced' is the definition.
('seasoned' can be similar in meaning to 'experienced')
'quite a lot of remorse as one does' is the wordplay.
'quite a lot of' indicates the answer is hidden within the clue (I've seen 'quite a lot' mean this).
'SEASONED' can be found hidden inside 'remorse as one does'.
(Other definitions for seasoned that I've seen before include "Veteran - given added flavour" , "Added spice to" , "Of food, flavoured with salt, pepper etc" , "Mature" , "Flavoured or hardened" .)