Very old lady upset Hebrew prophet (4)
I believe the answer is:
amos
'hebrew prophet' is the definition.
(I've seen this before)
'very old lady upset' is the wordplay.
'very' becomes 'so' (I've seen this in other clues).
'old lady' becomes 'ma' (**).
'upset' says the letters should be written backwards.
'so'+'ma'='soma'
'soma' back-to-front is 'AMOS'.
(Other definitions for amos that I've seen before include "man" , "Old Testament book" , "Prophet in the Bible" , "Hebrew prophet" , "Biblical character" .)