Once again look at ornament at back of study (9)
I believe the answer is:
readdress
'once again look at' is the definition.
(to look at or address again)
'ornament at back of study' is the wordplay.
'ornament' becomes 'dress' (dressing is a kind of ornamenting).
'at back of' is a charade indicator (letters next to each other).
'study' becomes 'read' (synonyms).
'dress' after 'read' is 'READDRESS'.
(Other definitions for readdress that I've seen before include "tackle again" , "Have another look at" , "change direction" , "forward" .)