Intent on Eastern reformation (7)
I believe the answer is:
earnest
'intent on' is the definition.
(thesaurus)
'eastern reformation' is the wordplay.
'reformation' indicates anagramming the letters.
'eastern' anagrammed gives 'EARNEST'.
(Other definitions for earnest that I've seen before include "Eastern (anag.)" , "Sincere or over-serious" , "Sneer at (anag) -- serious" , "Art worthy" , "Showing sincere and intense conviction" .)