Improve, as an argument (7)
I believe the answer is:
sharpen
(Other definitions for sharpen that I've seen before include "Raise pitch of" , "Restore edge to knife" , "Hone (a knife blade)" , "Make pointed" , "Put a keen edge on" .)
I believe the answer is:
sharpen
(Other definitions for sharpen that I've seen before include "Raise pitch of" , "Restore edge to knife" , "Hone (a knife blade)" , "Make pointed" , "Put a keen edge on" .)