A strophoid is a curve that looks like a loop, but it is not a circle.
The word strophoid is used in math and geometry.
Examples:
The strophoid is a math thing.
The strophoid is not a circle.
The strophoid is a kind of curve.
The strophoid is a funny shape.
The strophoid is a very strange curve.
The strophoid is a loop that is not a circle.