Wiktionary
n. (military) A satellite orbit where the orbital period is equal to, or multiples of, the Earth’s rotational period; i.e. making one, two, three, etc., orbits in a 24-hour period.
Wikipedia
Usage examples of "synchronous orbit".
The beanstalk control station, one of a dozen scattered between L-4 and synchronous orbit, permitted line-of-sight communications with Anson's office back on Earth.
The synchronous orbit is also closer - less than half the altitude here.
I piloted us over the pole and down to synchronous orbit on the far side, where we parked the shuttle and I activated the jammer mounted on the outer hull.
It was in synchronous orbit, hovering above a great landmass shaped like a broad arrowhead.
The buoy would then rise to the surface, orient a low-power transmitter towards the military satellite in gyro-synchronous orbit over the Philippine Sea and send an encrypted and condensed communication burst of the device’.
Vosnesensky was already sliding into the driver's chair and checking to see that their communications antenna was locked onto the spacecraft up in synchronous orbit.