Foolish or ridiculous behavior; silly conduct or tricks; the behavior, practices, or performance style of a clown.
From clown + -ery (a suffix meaning 'behavior, practices, or a collection of things'). Similar formations include 'wizardry,' 'snobbery,' and 'trickery.' The word has been used in English since at least the 17th century.
Shakespeare probably used 'clownery,' and it's still the perfect word for describing someone's ridiculous antics—it sounds like you're dismissing them with an entire theatrical performance rolled into one word.
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