American writer capturing southern attitude (4)
I believe the answer is:
pose
'attitude' is the definition.
(I've seen this before)
'american writer capturing southern' is the wordplay.
'american writer' becomes 'poe' (Edgar Allan Poe).
'capturing' indicates putting letters inside.
'southern' becomes 's' (abbreviation).
'poe' enclosing 's' is 'POSE'.
(Other definitions for pose that I've seen before include "Sit as model" , "Models do it for photographic or artistic purposes" , "front" , "Present (a question); sit" , "Present (problem), sit" .)