Achievement; exploit (4)
I believe the answer is:
This clue is a double definition.
'achievement' is the first definition.
(I know that feat is a type of achievement)
'exploit' is the second definition.
(I know that exploit can be written as feat)
(Other definitions for feat that I've seen before include "Achievement needing skill, strength, etc." , "An accomplishment of fate" , "Achievement needing great courage or skill" , "Courageous act" , "Exploit; achievement" .)