apsis

American  

[ap-sis] / ˈæp sɪs /

noun

• apsides
  plural

1. Astronomy. either of two points in an eccentric orbit, one higher apsis farthest from the center of attraction, the other lower apsis nearest to the center of attraction.

2. Architecture. an apse.

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apsis British  

/ ˈæpsɪs /

noun

1. Also called: apse. either of two points lying at the extremities of an eccentric orbit of a planet, satellite, etc, such as the aphelion and perihelion of a planet or the apogee and perigee of the moon. The line of apsides connects two such points and is the principal axis of the orbit

2. another name for apse

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apsis Scientific  

/ ăp′sĭs /

• apsides
  plural

1. 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.

2. See also apoapsis periapsis

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Other Word Forms

Derived Forms

• apsidal
  adjective

Inflected Forms

Nouns

• apsides
  plural

Etymology

Origin of apsis

1595–1605; < Latin < Greek hapsís (felloe of ) a wheel, arch, vault, originally, fastening, equivalent to háp ( tein ) to fasten + -sis -sis

Example Sentences

See Examples For:

apsis apsides

The list of relics on the right of the apsis of Sta.

From Walks in Rome by Augustus J. C. Hare

The more distant is called the higher apsis; the other, the lower apsis; and the line joining them, the line of apsides.

From Webster's Unabridged Dictionary by Noah Webster

But the most singular part of this church is the crypt under the apsis, a room about thirty feet long by fourteen wide, and sixteen high, of extreme simplicity, and remote antiquity.

From Account of a Tour in Normandy, Volume 1 by Dawson Turner

At the further end of this chamber was a stone altar, standing upon one or two steps, in an apsis or semicircular recess.

From Visits To Monasteries in the Levant by Robert Curzon

The earliest example of a more animated treatment is, perhaps, the figure in the apsis of St. John Lateran.

From Legends of the Madonna as Represented in the Fine Arts by Mrs. (Anna) Jameson

The time of revolution of a primary or secondary planet in reference to its line of apsides; that is, from one perigee or apogee to another.

From The Sailor's Word-Book An Alphabetical Digest of Nautical Terms, including Some More Especially Military and Scientific, but Useful to Seamen; as well as Archaisms of Early Voyagers, etc. by Sir Edward Belcher

Change of line of apsides; period about 21,000 years.

From Astronomical Curiosities Facts and Fallacies by J. Ellard Gore

The line of the apsides has a slow forward angular motion in the plane of the planet's orbit, being retrograde only in the case of Venus.

From The New Gresham Encyclopedia. Vol. 1 Part 2 Amiel to Atrauli by Various

Thirdly, the variations in the eccentricity of the earth's orbit, combined with the precession of the equinoxes and the rotation of the apsides, may be regarded as operative.

From Outlines of the Earth's History A Popular Study in Physiography by Nathaniel Southgate Shaler

Any persons whom it could please have no better notion of what the words referred to signify than of the meaning of apsides and asymptotes.

From The Atlantic Monthly, Volume 03, No. 20, June, 1859 by Various