Definition

1 : of or relating to stars or constellations

2 : measured by the apparent motion of the stars

Examples

David’s parents were so pleased by his newfound interest in sidereal phenomena that they bought him an expensive telescope for his birthday.

“Today, these various astronomical functions can mainly be found in very complicated watches…. These exceptional timekeepers are masterpieces of knowledge, technique and know-how, presenting a range of complex functions: display ofsidereal time, equation of time, hours of sunrise and sunset, star charts, angular movement of the moon, phases of the moon….” — Grégory Gardimer