Meanings
nounephemeris time (uncountable)
- uncountableastronomyA former standard astronomical time scale intended to overcome the drawbacks of irregularly fluctuating mean solar time, superseded in the 1970s.
- uncountableastronomyA modern relativistic-coordinate time scale.
Synonyms & antonyms
noun(astronomy) a measure of time defined by Earth's orbital motion; terrestrial time is mean solar time corrected for the irregularities of the Earth's motions
Broader
Synonym sets from Open English WordNet, CC BY 4.0.
Cite this entry
APA
ephemeris time. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/ephemeris%20time
MLA
“ephemeris time.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/ephemeris%20time. Accessed November 4, 2026.
Chicago
WatkinsX Dictionary, s.v. “ephemeris time,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/ephemeris%20time.
Source: ephemeris time on Wiktionary, CC BY-SA 4.0.