Phrase guide

sidereal day

noun · 3 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

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1

noun

Meaning 1

One day of sidereal time; the time in which Earth rotates once around its axis, relative to the point of the vernal equinox (about 23 hours, 56 minutes, 4 seconds).

Definition source: English Wiktionary via Wiktextract

Topics: astronomy, natural-sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

The rotational period of Earth; the time in which Earth rotates around its axis 360 degrees.

Definition source: English Wiktionary via Wiktextract

Topics: astronomy, natural-sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

3

noun

Meaning 3

the time for one complete rotation of the earth relative to a particular star, about 4 minutes shorter than a mean solar day

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: day

Antonyms: none provided

Broader terms: time unit, unit of time, sidereal time

History

Etymology

No etymology was provided for this word.

Across languages

Translations

9 source translations are retained for this English entry.

  • Chinese Mandarin: 恆星日 /恒星日 (héngxīngrì) — day of sidereal time
  • Dutch: siderische dag — day of sidereal time
  • Finnish: sideerinen vuorokausi — day of sidereal time
  • French: jour sidéral — day of sidereal time
  • German: siderischer Tag — day of sidereal time
  • German: Sterntag — day of sidereal time
  • Japanese: 恒星日 (kōseijitsu) — day of sidereal time
  • Romanian: zi siderală — day of sidereal time
  • Russian: звёздные су́тки (zvjózdnyje sútki) — day of sidereal time