roundel

/หˆษนaสŠn.dษ™l/
noun
  1. 1

    Anything having a round form; a round figure; a circle.

    โ€œthe London Underground roundelโ€

  2. 2

    A roundelay or rondelay.

  3. 3

    A small circular shield, sometimes not more than a foot in diameter, used by soldiers in the fourteenth and fifteenth centuries.

  4. 4

    A circular spot; a charge in the form of a small coloured circle.

  5. 5

    A circular insignia painted on an aircraft to identify its nationality or service.

  6. 6

    A bastion of a circular form.

Synonyms

Source: https://en.wiktionary.org/wiki/roundel