noun, plural ap·si·des [ap-si-deez] /ˈæp sɪˌdiz/.
Origin of apsis
Examples from the Web for apsides
Historical Examples of apsides
The two are joined by a diameter called the line of the apsides.The Sailor's Word-Book
William Henry Smyth
The line of apsides of a large proportion of comets will be approximately coincident with the solar orbit.Comets and Meteors
The “line of apsides” is that which joins them, forming the major axis of the orbit.
This point was called "the excentric," and the line from the excentric to the Earth was called "the line of apsides."The Science of the Stars
E. Walter Maunder
The line of the apsides of the moon's orbit revolves from west to east, through her whole course, in about nine years.Letters on Astronomy
noun plural apsides (æpˈsaɪdiːz, ˈæpsɪˌdiːz)
Word Origin for apsis
"perigree of the moon, perihelion of a planet" (plural apsides), 1650s, from Latin apsis "arch, vault" (see apse).