apsis

noun
ap·​sis | \ ˈap-səs How to pronounce apsis (audio) \
plural apsides\ ˈap-​sə-​ˌdēz How to pronounce apsides (audio) \

Definition of apsis

1 : the point in an astronomical orbit at which the distance of the body from the center of attraction is either greatest or least

First Known Use of apsis

1601, in the meaning defined at sense 1

History and Etymology for apsis

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

Keep scrolling for more

Learn More about apsis

Time Traveler for apsis

Time Traveler

The first known use of apsis was in 1601

See more words from the same year

Statistics for apsis

Cite this Entry

“Apsis.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/dictionary/apsis. Accessed 26 January 2020.

More from Merriam-Webster on apsis

Britannica.com: Encyclopedia article about apsis

Comments on apsis

What made you want to look up apsis? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

to express in a more acceptable way

Get Word of the Day daily email!

Test Your Vocabulary

Intact Latin Quiz

  • roman tablet
  • What did focus mean in Latin?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Bee Cubed

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!