Circumcircles

Part of speech: verb

Definitions

1. A circle that passes through all the vertices of a polygon, encompassing the entire shape within its boundary
2. The locus of points equidistant from a central point that serves to touch each corner of a defined geometric figure
3. An enclosing circle drawn around a polygon that includes all its angular points, ensuring they lie on its circumference

Etymology: The plural "circumcircles" is simply the plural of "circumcircle," a compound built from the Latin prefix "circum-," meaning "around," and the English word "circle." Each circumcircle is therefore a circle drawn around something, here a polygon, passing through every one of its corners. The plural form is what you need when a figure has several such enclosing circles, or when a discussion covers more than one polygon. The construction is a plain technical coinage in geometry rather than a word with a dramatic backstory. Its meaning follows the parts directly: "circum-" supplies the sense of surrounding, and "circle" supplies the shape, so the whole term names the circle that encloses the figure.