It, of course depends on how the term is being used. For a long time gyros were used, as colorex said, as a single axis control. Mostly in helicopters to help keep the yaw in check. Then folks got the idea to take two, or even three gyros and mount them on planes, to help with all three axises.
There were cases where three gyros would be placed into a single device, with the intention of helping control all three axises for helicopters, and planes. This became more common once multirotors were created.
Then you have the experiments using the accelerometers from Wii controllers. These had the advantages of gyros, but with greater sensitivity. In some cases you might be seeing flight controllers using accelerometers instead of gyros, so they called them stabilizers since there were no gyros in them.
