Boastful (12)
I believe the answer is:
vainglorious
'boastful' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for vainglorious that I've seen before include "Self-important -- savouring oil (anag)" , "Excessively self-important" , "Overly self-regarding" , "Egotistic" , "Boastful; rousing viola (anag.)" .)