roundlet

plural roundlets

1. A small disk, circle or other round object.

   The annexed arrangements of roundlets in shields will show how they are placed and described.

   1894, Sir Francis James Grant, The Manual of Heraldry, page 37

   2 more examples

   […] let the water continue on the fire a Pater noster while, then take it off, and being cold, put the ſame into ſome roundlet, filling the roundlet brim full.

   1653, Sir Hugh Plat, The Jewel House of Art and Nature

   The basis of the chaperon was a wreath-like pad, called a bourlet or roundlet (not unlike a miniature motor-tyre), encircling the temples.

   2011, Dorothy Hartley, Medieval Costume and How to Recreate It, page 91

   Synonyms: rondel