[ih-fem-er-is] /ɪˈfɛm ər ɪs/
noun, plural ephemerides
[ef-uh-mer-i-deez] /ˌɛf əˈmɛr ɪˌdiz/ (Show IPA)
a table showing the positions of a heavenly body on a number of dates in a regular sequence.
an astronomical almanac containing such tables.
Archaic. an almanac or calendar.
noun (pl) ephemerides (ˌɛfɪˈmɛrɪˌdiːz)
a table giving the future positions of a planet, comet, or satellite
an annual publication giving the positions of the sun, moon, and planets during the course of a year, information concerning eclipses, astronomical constants, etc
(obsolete) a diary or almanac
table showing predicted positions of heavenly bodies, 1550s, Modern Latin, from Greek ephemeris “diary, calendar,” from ephemeros “daily” (see ephemera). The classical plural is ephemerides.
Plural ephemerides (ěf’ə-měr’ə-dēz’)
A table giving the coordinates of a celestial body at specific times during a given period. Ephemerides can be used by navigators to determine their longitude while at sea and by astronomers in following objects such as comets. The use of computers has allowed modern ephemerides to determine celestial positions with far greater accuracy than in earlier publications.
noun, Astronomy. 1. the unit of ephemeris time, defined as a precise fraction of the length of the tropical year 1900.
noun, Astronomy. 1. time measured by the orbital movements of the earth, the moon, and the planets. noun 1. time that is based on the orbit of the earth around the sun rather than the axial rotation of the earth, one ephemeris second being 1/31 556 925.9747 of the tropical year 1900. It was used […]
[ih-fem-uh-ron, -er-uh n] /ɪˈfɛm əˌrɒn, -ər ən/ noun, plural ephemera [ih-fem-er-uh] /ɪˈfɛm ər ə/ (Show IPA), ephemerons. 1. anything short-lived or ephemeral. 2. ephemera, items designed to be useful or important for only a short time, especially pamphlets, notices, tickets, etc. /ɪˈfɛməˌrɒn/ noun (pl) -era (-ərə), -erons 1. (usually pl) something transitory or short-lived n. […]
[ih-fem-uh-rop-ter-uh n] /ɪˌfɛm əˈrɒp tər ən/ adjective 1. belonging or pertaining to the insect order Ephemeroptera, comprising the mayflies. noun 2. . /iːˌfɛməˈrɒptərən/ noun 1. another word for ephemerid adjective 2. of or relating to the Ephemeroptera