ephemeris second


noun Astronomy.

the unit of ephemeris time, defined as a precise fraction of the length of the tropical year 1900.

Nearby words

  1. ephemera,
  2. ephemeral,
  3. ephemerality,
  4. ephemerid,
  5. ephemeris,
  6. ephemeris time,
  7. ephemeron,
  8. ephemeropteran,
  9. ephemerous,
  10. ephes.

Origin of ephemeris second

First recorded in 1965–70

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019