The orbit that an astronomical body such as a planet, asteroid, comet or satellite would follow if suddenly all perturbing forces other than the gravitational attraction of the Sun or (for a satellite) its planet were to disappear.

(astrophysics) geostationary Earth orbit / (astrophysics) geostationary orbit (an orbit around any body)

(anatomy) Situated behind the orbit or the eye.

In a retro-orbital direction.

(astronomy) The surface (plane) that contains an orbit.

(anatomy) An eye socket.

(anatomy) An eye socket.

(quantum mechanics, chemistry) A mathematical function that describes the wave-like behavior of either one electron or a pair of electrons in an atom. This function can be used to calculate the probability of finding any electron of an atom in any specific region around the atom's nucleus.

(quantum mechanics, chemistry) The quantum mechanical behaviour of an electron in a molecule describing the probability of the electron's particular position and energy; approximated by a linear combination of atomic orbitals.

(physics, chemistry) The properties of an atomic orbital or molecular orbital that characterize its symmetry; especially those properties that are conserved in a chemical reaction.