rondelle

A disk of colored glass, used as a decoration in stained-glass windows. Compare bull’s-eye, 8.

Something round.

In metallurgy, one of successive crusts which form upon the surface of molten metal while cooling, and which as they form are removed for further treatment.

Milit.: A small shield (15 inches in length) formerly used by pikemen and archers.

One of the iron disks, each having an opening in the center for the passage of a bolt, placed between the cheeks and stock of a field-gun carriage in bolting these parts together.

A semicircular bastion introduced by Albert Dū rer. It was about 300 feet in diameter, and contained spacious casemates.