1. (Astron.)
Defn: Of or pertaining to the apsides of an orbit.
2. (Arch.)
Defn: Of or pertaining to the apse of a church; as, the apsidal termination of the chancel.
APSIDES
Ap"si*des, n. pl.
Defn: See Apsis.
APSIS
Ap"sis, n.; pl. Apsides. See Apse. Etym: [L. apsis, absis, Gr.
1. (Astron.)
Defn: One of the two points of an orbit, as of a planet or satellite, which are at the greatest and least distance from the central body, corresponding to the aphelion and perihelion of a planet, or to the apogee and perigee of the moon. The more distant is called the higher apsis; the other, the lower apsis; and the line joining them, the line of apsides.
2. (Math.)