To take great pleasure or delight in something, or to celebrate and party loudly.
From Old French 'reveler' (to turn around, to rouse), possibly from Latin 'rebello' (to rebel). The celebratory sense emerged in the 16th century.
Medieval 'revels' were actual festivals that could get so wild they'd be banned by authorities—the word originally meant chaotic turning or twisting, which fits wild partying perfectly.
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