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

plural of Hohmann transfer orbit

(space flight) A lunar-resonant orbit about the Earth with a period of 1/2 that of the Moon's (P/2 is an orbit that is approximately a fortnight long)

(algebra) A theorem which states that for each element of a given set that a given group acts on, there is a natural bijection between the orbit of that element and the cosets of the stabilizer subgroup with respect to that element.

(science fiction) A satellite or space station, found in many different works of science fiction, meant to defend a planet against attack from space.

(of a black hole) Synonym of photon sphere

(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.

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