# sidereal

> English word · Adjective · IPA /saɪˈdɪə.ɹi.əl/ · frequency rank #74,505

## Definitions
1. Of or relating to the stars.
2. Relating to a measurement of time relative to the position of the stars.
3. Relating to a measurement of time relative to the point of the vernal equinox.

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

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/sidereal