diurnal motion (English, noun)
expansion: diurnal motion (uncountable)
Senses:
topics: astronomy
natural-sciences
glosses: The apparent westward rotation of the celestial sphere, along with the apparent westward revolution of celestial objects, around the celestial poles due to prograde (eastward) rotation of planet Earth relative to the seemingly fixed stars – completed once each sidereal day (about 23 hours, 56 minutes, 4 seconds).
tags: uncountable
Forms: