ephemeris time

Từ điển Oxford Learners Wordfinder Dictionary

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
• Syn:
terrestrial time, TT, terrestrial dynamical time, TDT
• Topics:
astronomy, uranology
• Hypernyms:
time unit, unit of time