Heard about US writer's affectation (4)
I believe the answer is:
pose
'affectation' is the definition.
(pose is a kind of affectation)
'heard about us writer's' is the wordplay.
'heard' becomes 'e' (I've seen this in other clues).
'about' means one lot of letters go next to another.
'us writer's' becomes 'pos' (I am not sure about this - if you are sure you should believe this answer much more).
'e' after 'pos' is 'POSE'.
Can you help me to learn more?
(Other definitions for pose that I've seen before include "Pretence" , "Sit as model" , "Model - ask (question)" , "Attitudinise" , "Sit; attitude" .)