Boastful (12)
I believe the answer is:
vainglorious
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">boastful</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(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.)" .)