Definition of lunar day in English:

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lunar day


1The interval of time between two successive crossings of the earth’s meridian by the moon (roughly 24 hours and 50 minutes).
Example sentences
  • Thus their ‘day’ would not be based on the movement of the Sun, a 24-hour cycle, but rather a lunar day, lasting 24 hours and 50 minutes.
  • The length of the lunar day is thus identical to the length of its revolution around Earth.
  • Based on lunar day of 24 hrs 50 minutes, will provide accurate indication of tide cycle.
2 rare The interval of time between two successive sunrises as seen from the moon.
Example sentences
  • It was designed to operate for three lunar days, but the scientific team succeeded in keeping it operating for eleven lunar days - the equivalent of 10 months.
  • Over the month-long lunar day, we'd see the Earth turn in place every 24 hours.

For editors and proofreaders

Syllabification: lu·nar day

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