Pound note remains (4)
I believe the answer is:
bash
'pound' is the definition.
(I've seen this in another clue)
'note remains' is the wordplay.
'note' becomes 'b' (musical note).
'remains' becomes 'ash' (remains of a fire).
'b'+'ash'='BASH'
(Other definitions for bash that I've seen before include "Strike violently" , "Try - rave-up" , "Batter" , "Break - party" , "Party - clobber" .)