Ran off to develop edgy feature? (6)
I believe the answer is:
eloped
'ran off' is the definition.
('elope' can be a synonym of 'run off')
'to develop edgy feature?' is the wordplay.
'feature?' indicates the answer is hidden within the clue (I've seen 'featuring' mean this).
'ELOPED' can be found hidden inside 'to develop edgy'.
(Other definitions for eloped that I've seen before include "Went off" , "Ran away to marry" , "Ran away to get married" .)