In general, an algebraic curve that passes through these two points is called circular.
If they coincide, the curve is called a loop.
The curve is usually called a trajectory or an orbit.
Less commonly, the inward curve of the body near the bottom may also be called a tumblehome.
In the case of roads, such curves, if tight enough, are typically called hairpin turns.
This curve is then called the development of the curve x.
This curve is called the "line of perfect inequality."
This curve is called the "'characteristic"' of the family at "a".
The two curves are called isogenous if there is an isogeny between them.
The inside surface retains its natural shape and the curve is called the bosom.