Poor actor in South East — pity (5)
I believe the answer is:
shame
'pity' is the definition.
(I've seen this before)
'poor actor in south east' is the wordplay.
'poor actor' becomes 'ham' (I've seen this before).
'in' indicates putting letters inside.
'south east' becomes 'se'.
'ham' going into 'se' is 'SHAME'.
(Other definitions for shame that I've seen before include "show up" , "pity!" , "Disgrace - Salman Rushdie novel" , "Humiliation; dishonour" , "disgraceful" .)