Dad getting over friend’s outrage (5)
I believe the answer is:
appal
'outrage' is the definition.
(I know that outrage can be written as appal)
'dad getting over friend's' is the wordplay.
'dad' becomes 'pa' (both can mean one's father).
'getting over' shows that the letters should be reversed in order (flipped over).
'friend' becomes 'pal' (pal can mean a friend).
'pa' in reverse letter order is 'ap'.
'ap'+'pal'='APPAL'
(Other definitions for appal that I've seen before include "To shock, dismay" , "Greatly horrify" , "Disgust" , "Dismay, horrify" , "Fill with horror" .)