roundel
Concise Oxford English Dictionary © 2008 Oxford University Press:
roundel /ˈraʊnd(ə)l/
▶noun
- 1 a small disc, especially a decorative medallion.
■ a circular identifying mark painted on military aircraft.
- 2 a variation of the rondeau (poem), consisting of three stanzas of three lines each, rhyming alternately, with the opening words repeated as a refrain after the first and third stanzas.
'roundel' also found in these Oxford entries:

