roundel

noun

1. Rare, Archaic something round, or circular
2. a round ornamental panel, plate, niche, etc.
3. a small, round window or pane
4. 1. Archaic a rondeau
   2. an English variation of the rondeau, with eleven lines (three stanzas), the fourth and eleventh being the refrain
5. roundelay (sense )

Origin: ME < OFr rondel, orig. dim. of roont, round