vainglorious
vainglory + -ous
https://gyazo.com/8b3b6aac40f4a322b781564eb22971e9
adjective literary
excessively proud of oneself or one's achievements; overly vain:
｟文｠ うぬぼれ［虚栄心］の強い
e.g. this vainglorious boast of personal infallibility.
DERIVATIVES
vaingloriously |ˌvānˈɡlôrēəslē| adverb
vaingloriousness |ˌvānˈɡlôrēəsnəs| noun