orbicular

Circular or spherical in shape; round.

[…] the Method used by Sailors when they mutiny, by signing their names in an orbicular manner, which they call a round Robin; […]

The whole covey of victims was thus netted; the household ruin was thus full and orbicular; and in that proportion the tendency of men and women, flutter as they might, would be helplessly and hopelessly to sink into the all-conquering hands of the mighty murderer.

Of a muscle, surrounding an opening; compare orbicularis.

Pertaining to an orbicula.