girth

The girth of something is the distance around its middle, and it usually refers to a person’s waist. If you get pregnant with twins, your girth will probably block your view of your toes.

One can measure the girth of an airplane, tree trunk, or anything cylindrical, but it most often describes a large human waist. We don't usually describe a rail-thin person as having 'minuscule girth," — but when Aunt Velma has her seventh helping of lasagna and has to unbuckle her belt, she might announce, "My girth has outsized my attire!" Girth can also mean a strap that encircles the belly of a horse, mule, or other animal to secure a load.