When planets, moons, or spacecraft move around other objects in an orbit — a curved, regular path — you can describe this movement as orbital. An orbital period is the length of time it takes a craft or body to make a complete pass around the object it orbits. Another way to use this adjective is to mean "relating to an eye socket," which is actually its earliest meaning. The Latin root is orbita, "wheel track, beaten path, course, or orbit."