Eastern cause arousing intense feeling (7)
I believe the answer is:
emotive
'arousing intense feeling' is the definition.
(I've seen this before)
'eastern cause' is the wordplay.
'eastern' becomes 'e'.
'cause' becomes 'motive' (**).
'e'+'motive'='EMOTIVE'
(Other definitions for emotive that I've seen before include "Moving - controversial" , "arousing passion" , "Affecting, moving" , "Arousing deep feeling" , "exciting" .)