Of or having an orbit with a fixed period of 24 hours (although the position in the orbit may not be fixed with respect to the earth) WordNet 3.0 & Open English WordNet

Refers to the orbit of a satellite whose rate of revolution is matched to the rotation period of the Earth. A special case is the geostationary orbit which is circular and equatorial, so that the satellite appears to be fixed over a particular point on Earth's sky. Wiktionary

Orbit whose rate of revolution is matched with Earth. Wiktionary (translation)