Circumference
In geometry, the circumference (from Latin circumferentia, meaning “carrying around”) of a circle is the (linear) distance around it. That is, the circumference would be the length of the circle if it were opened up and straightened out to a line segment. Since a circle is the edge (boundary) of a disk, circumference is a special case of perimeter. The perimeter is the length around any closed figure and is the term used for most figures excepting the circle and some circular-like figures such as ellipses.
Informally, “circumference” may also refer to the edge itself rather than to the length of the edge.
Circumference (noun)
The line that bounds a circle or other two-dimensional figure
Circumference (noun)
The length of such a line
Circumference (noun)
The surface of a round or spherical object
Circumference (noun)
The length of the longest cycle of a graph
Circumference (verb)
To include in a circular space; to bound.
Girth (noun)
A band passed under the belly of an animal, which holds a saddle in place.
Girth (noun)
The part of an animal around which the girth fits.
Girth (noun)
One’s waistline circumference, most often a large one.
Girth (noun)
A small horizontal brace or girder.
Girth (noun)
The distance measured around an object.
Girth (noun)
The length of the shortest cycle in a graph.
Girth (verb)
To bind as if with a girth or band.
Circumference (noun)
the enclosing boundary of a curved geometric figure, especially a circle.
Circumference (noun)
the distance around something
“babies who have small head circumferences”
“a rope two inches in circumference”
Girth (noun)
the measurement around the middle of something, especially a person’s waist
“an ivy-clad tree of immense girth”
“a pike with a girth of 24 inches”
“idle men of great girth”
Girth (noun)
a person’s waist or stomach, especially when large
“he tied the knotted towels around his girth”
Girth (noun)
a band attached to a saddle and fastened around a horse’s belly to keep the saddle in place.
Girth (verb)
surround; encircle
“the four seas that girth Britain”