Unorthodox Easter saint (6)
I believe the answer is:
teresa
'saint' is the definition.
(I've seen this before)
'unorthodox easter' is the wordplay.
'unorthodox' indicates an anagram.
'easter' anagrammed gives 'TERESA'.
(Other definitions for teresa that I've seen before include "Mother of Calcutta, 1910-97" , "Saint" , "Mother ..., who ministered to the poor in India" , "Nun who was dedicated to helping the poor of Calcutta" , "Late nun, dedicated to helping the poor in India" .)