*roundel*

n. [ OF. rondel a roundelay, F. rondel, rondeau, a dim. fr. rond; for sense 2, cf. F. rondelle a round, a round shield. See Round, a., and cf. Rondel, Rondelay. ] 1. (Mus.) A rondelay. “Sung all the roundel lustily.” Chaucer. [ 1913 Webster ]

Come, now a roundel and a fairy song. Shak. [ 1913 Webster ]

2. Anything having a round form; a round figure; a circle. [ 1913 Webster ]

The Spaniards, casting themselves into roundels, . . . made a flying march to Calais. Bacon. [ 1913 Webster ]

Specifically: (a) A small circular shield, sometimes not more than a foot in diameter, used by soldiers in the fourteenth and fifteenth centuries. (b) (Her.) A circular spot; a sharge in the form of a small circle. (c) (Fort.) A bastion of a circular form. [ 1913 Webster ]