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Added 10 October 2026

sidereal

/saɪˈdɪə.ɹi.əl/ adjective

Latin root: sīdereus Wiktionary

adjective Definition from Wiktionary (CC BY-SA). Pronunciation from Wiktionary, via Kaikki.org. More about sidereal at Wordnik → Where our words come from →

Of or relating to the stars.
Relating to a measurement of time relative to the position of the stars.
Relating to a measurement of time relative to the point of the vernal equinox.

Origin

From Latin sīdereus + -al (cf. Latin sīderālis), from sīdus (“star, constellation”), of unknown ultimate origin, likely a substrate language such as Pre-Greek.

From Wiktionary, via Kaikki.org (CC BY-SA)

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