ap·​sis ˈap-səs How to pronounce apsis (audio)
plural apsides ˈap-sə-ˌdēz How to pronounce apsis (audio)
: the point in an astronomical orbit at which the distance of the body from the center of attraction is either greatest or least

Examples of apsis in a Sentence

Recent Examples on the Web Each term is sometimes called an apsis, which refers to the nearest or farthest point between a celestial body and its host. NBC News, 5 Jan. 2022

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'apsis.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


borrowed from Medieval Latin apsīs, apsīda "arc, vault," going back to Latin apsīd-, apsīs (also hapsīs, absīs) "arc described by a planet, segment of a circle," borrowed from Greek hapsīd-, hapsís (Ionic apsís) "loop, mesh, rim of a wheel, wheel, disk, segment cut off by a rainbow, arch, vault," from ap-s-, stem in noun derivation of háptein "to fasten," háptesthai "to fasten oneself to, grasp" + -īd-, -īs, noun suffix — more at haptics

First Known Use

1601, in the meaning defined at sense 1

Time Traveler
The first known use of apsis was in 1601

Dictionary Entries Near apsis

Cite this Entry

“Apsis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/apsis. Accessed 6 Dec. 2023.

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