An Etymological Dictionary of Astronomy and Astrophysics

The path followed by a body moving in a gravitational field. For bodies moving under the influence of a centrally directed force, without significant perturbation, the shape of the orbit must be one of the conic section family of curves (circle, ellipse, parabola, or hyperbola).

Etymology (EN): L. orbita “wheel track, course, circuit.”

Etymology (PE): Madâr, from Ar.