Meaning

noun periapsis in solar orbit; the point in the orbit of a planet or comet where it is nearest to the sun

originPIE word *sóh₂wl̥ From perihelium (“perihelion”) (obsolete) + -ion (suffix used for other names of apsides). Perihelium is borrowed from Late Latin perihelium, from Ancient Greek περι- (peri-, “around; surrounding”), ultimately from Proto-Indo-European *per- (“before, in front; first”)) + ἥλιος (hḗlios, “sun”) (ultimately from Proto-Indo-European *sóh₂wl̥ (“sun”)), which was modelled after…

Etymology from Wiktionary, CC BY-SA 3.0