perihelion noun. [pɛrɪ'hi:lɪǝn] Also perihelium. Pl. -lia [-lɪǝ]. M17.
[Graecized form of mod. Latin perihelium, formed as PERI- + Greek hēlios sun.]
1. Astronomy. The point in the orbit of a planet, comet, etc., at which the closest distance from the sun is reached. M17.

2. fig. The highest point, the zenith. E19.

[TahlilGaran] English Dictionary ▲