What is the definition of Sesquipedalian:

Sesquipedalian: A long polysyllabic word that means having many syllables or using long words.

From the Latin sesqui- meaning one and a half times + ped, pes meaning foot. In Ars Poetica, the Roman poet Horace cautioned young poets against using "sesquipedalia verba" -- "words a foot and a half long."

For example:

Pneumonoultramicroscopicsilicovolcanosconiosis.

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