What is a kind of lyric poetry in honor of Bacchus, usually sung by a band of revelers to a flute accompaniment; hence, in general, a poem written in a wild irregular strain. Bentley called?

dithyramb — A kind of lyric poetry in honor of Bacchus, usually sung by a band of revelers to a flute accompaniment; hence, in general, a poem written in a wild irregular strain. Bentley. (Webster's 1913.)

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