the period of revolution of one object around another measured with respect to the stars (e.g., for the Moon, it is 27.3 days).
A period determined by or from the stars. [ 39
The period of revolution of one body about another measured with respect to the stars.
A rotational or orbital period of time with a fixed stellar Point taken as reference.
The orbital period relative to the stars.
The period of revolution of a planet around the Sun or a satellite around its primary.
The sidereal period is the time it takes a planet (or other body) to complete one orbit around the sun (with reference to the stars). It is usually expressed in Earth years.