What term describes the time for one complete rotation of the Earth relative to a particular star?

The term that describes the time for one complete rotation of the Earth relative to a particular star is sidereal time. This concept is fundamental in astronomy and is based on the Earth's rotation period concerning distant celestial objects, which are effectively static from our point of view.

Unlike solar time, which measures the Earth's rotation relative to the position of the sun and is influenced by the elliptical orbit of the Earth, sidereal time provides a more consistent measurement of time based on the stars. One complete rotation of the Earth takes about 23 hours, 56 minutes, and 4 seconds, which defines a sidereal day. This is shorter than a solar day, which is approximately 24 hours because the Earth also moves slightly along its orbit around the sun during the time it takes to complete one rotation.

Universal Time and mean time are both related to solar time but are used to describe timekeeping methods that average variations in the Earth's rotation. Mean time tries to smooth out irregularities in solar time, while universal time provides a standard reference around the world. Thus, sidereal time stands out specifically for its relationship to stars, making it the precise answer to the question about Earth's rotation relative to celestial objects.