A*phel"ion (?; 277), n.; pl. Aphelia (&?;). [Gr. &?; + &?; sun.] (Astron.) That point of a planet's or comet's orbit which is most distant from the sun, the opposite point being the perihelion.

• the point in the elliptical orbit of a planet, comet, etc., where it is farthest from the sun