The supreme or chief fool; a master jester or the most ridiculous buffoon.
From arch- (principal, supreme) + buffoon (from Italian buffo 'ridiculous'). The term applies arch- to intensify buffoon into the ultimate fool. It could refer ironically to someone failing spectacularly, or literally to the head jester at a royal court.
Calling someone an 'archbuffoon' was the ultimate medieval insult wrapped in fancy language—you're not just making a fool of yourself, you're the *supreme* fool, the varsity team of ridiculous. Kings actually employed head jesters with this kind of status.
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