Poet abusing red pens (7)
I believe the answer is:
spender
'poet' is the definition.
(Stephen Spender)
'abusing red pens' is the wordplay.
'abusing' indicates an anagram (I've seen 'abused' mean this).
'red'+'pens'='redpens'
'redpens' anagrammed gives 'SPENDER'.
(Other definitions for spender that I've seen before include "Profligate" , "who is just 31[WINDOW SHOPPER]? No" , "poet, communist" , "writer of poetry" , "Sir Stephen -, English twentieth century poet" .)