roundels

noun

1. 1

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

   “the London Underground roundel”

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.