US author finally put down US painter (6)
I believe the answer is:
rothko
'down us painter' is the definition.
'rothko' can be an answer for 'painter' (Mark Rothko, 1903-1970). I am unsure of the 'down us' bit.
'us author finally' is the wordplay.
'us author' becomes 'Roth' (novelist Philip Roth).
'finally' becomes 'ko' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'roth'+'ko'='ROTHKO'
'put' is the link.
Can you help me to learn more?
(Other definitions for rothko that I've seen before include "Mark --, US abstract painter" , "Sudden violent release" , "Mark --, US artist" , "US abstract expressionist" .)