Do you know a thrasonical person, someone who's always bragging, acting superior, or making exaggerated claims? If so, you've probably discovered that being thrasonical is a real turn-off!
Thrasonical comes from Thraso, the name of a character in a comedy called The Eunuch, written by a Roman playwright in the 2nd century BCE. In the play, Thraso is a rich, arrogant army officer who boasts and brags to impress a woman. Apparently the play was very successful, but it wasn't entirely original: The playwright, Terence, borrowed the basic story and characters from an earlier Greek play written by Menander. Feel free to impress people by using the fancy word thrasonical and telling the story about its origins — but try not to act in a thrasonical manner when you do so!