ˈapsə̇s noun
( plural apsi·des -psəˌdēz, apˈsī(ˌ)dēz)
Etymology: Latin apsis, absis, from Greek apsid-, apsis, hapsid-, hapsis loop, wheel, arch, orbit, from haptein to fasten; perhaps akin to Greek oiphein to copulate with, Sanskrit yabhati he copulates with
1. obsolete : circumference , orbit
2.
[New Latin, from Latin]
: the point in an orbit at which the distance of the body from the center of attraction is either greatest or least (as the apogee or perigee of the moon or the aphelion or perihelion of a planet)
3.
[Medieval Latin, from Latin]
: apse 1