aphelion

Etymology

Comes from New Latin aphēlium (which gave English aphelium, now displaced) plus -ion (used in the names of other apsides). Aphelium itself was formed from Ancient Greek ἀπο- (apo-, a prefix meaning 'away, from, off') and ἥλῐος (hḗlĭos, 'the sun') — ultimately from Proto-Indo-European *sóh₂wl̥ ('the sun') — modelled on New Latin apogaeum ('apogee'). The plural, aphelia, comes from aphelion plus -a (the plural form of the suffix -on).