Thrasonical - adj. boastful; vainglorious.
I found thrasonical while browsing through some old episodes of Merriam-Webster’s Word of the Day Podcast.
This fancy word comes from a boastful character named Thraso, who appeared in the comedy Eunuchus. Though you won’t use it often, thrasonical could definitely come in handy if you have a bragging, word-loving character. “I’m not arrogant; I’m thrasonical!”