Perihelion \Per`i*hel"ion\, Perihelium \Per`i*he"li*um\, n.; pl.
{Perihelia}. [NL., fr. Gr. peri` about, near + "h`lios the
sun.] (Astron.)
That point of the orbit of a planet or comet which is nearest
to the sun; -- opposed to {aphelion}.
[1913 Webster]