Sentence:  "Ay, fool," said Tristram, "but 'tis eating dry / To dance without a catch, a <WSD>roundelay</WSD> / To dance to." Then he twangled on his harp, / And while he twangled little Dagonet stood / Quiet as any water-sodden log / Stay'd in the wandering warble of a brook;... 
Meaning of the word marked with <WSD> tags:  A poem or song having a line or phrase repeated at regular intervals.