(physics, chemistry) A method of determining the structure of a molecule by assuming that electrons are not fixed to bonds between individual atoms

(ophthalmology, neurology) A collection of cranial nerve deficits associated with a mass lesion near the apex of the orbit, often leading to ophthalmoplegia.

(anatomy) One of two openings transmitting nerves and blood vessels to or from the orbit, situated inferiorly between the greater wing of the sphenoid bone and the maxilla.

(anatomy) One of two openings transmitting nerves and blood vessels to or from the orbit, situated superiorly between the greater wing and the lesser wing of the sphenoid bone.

(astrodynamics) A nearly polar orbit in which a satellite passes over the surface of a planet maintaining the same local mean solar time.

plural of P/2 orbit

(informal, often humorous) The referent of it is dangerous or undesirable and should be eliminated.

plural of sidereal orbital period

(aerospace) An elliptical orbit used to transfer between two circular orbits of different radii in the same plane.

plural of Hohmann transfer orbit