apsis

ap·sis  (pss)

n. pl. ap·si·des (-s-dz)

1. Architecture An apse.

2. Astronomy The point of greatest or least distance of the orbit of a celestial body from a center of attraction.

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[Late Latin, from Latin, arch, vault, from Greek hapsis, from haptein, to fasten.]

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apsis [ap-siss, ap-sid-deez]

Noun

pl apsides Astron either of two points lying at the extremities of the elliptical orbit of a planet or satellite [see apse]

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apsis  (pss)

Plural apsides (ps-dz)

In the path of an orbiting body, either of the two points at which it is closest to or farthest away from the body it is orbiting. See also apoapsisperiapsis

Thesaurus

Noun

1.

apsis - a domed or vaulted recess or projection on a building especially the east end of a church; usually contains the altar apse church building, church - a place for public (especially Christian) worship; "the church was empty" niche, recess - an enclosure that is set back or indented tribune - the apse of a Christian church that contains the bishop's throne