- A rondelay. - Anything having a round form; a round figure; a circle. - A small circular shield, sometimes not more than a foot in
diameter, used by soldiers in the fourteenth and fifteenth centuries. - A circular spot; a sharge in the form of a small circle. - A bastion of a circular form.
Meaning of 'roundel' (Princeton's WordNet)
1 . roundel
[ n]
Meaning (1): - (heraldry) a charge in the shape of a filled circle