How do you spell Orbit

Available Definitions:
1)  n. - The path described by a heavenly body in its periodical revolution around another body; as, the orbit of Jupiter, of the earth, of the moon.
2)  n. - An orb or ball.
3)  n. - The cavity or socket of the skull in which the eye and its appendages are situated.
4)  n. - The skin which surrounds the eye of a bird.