A very good question Philosoraptor. An earthquake is what it is, because the Earth is “quaking”. Quake is a term used to describe shaking of something due to a release of energy. When there is a release of energy within the Earth due to tectonics or whatever, that energy disperses through the Earth in a series of waves that we feel and observe as earthquakes.
This phenomenon is not unique to Earth, or even to planets, and when they occur, they are named properly. Scientists have recorded, observed or inferred moonquakes, marsquakes, venusquakes, sunquakes and even starquakes. Any planet or astronomical body can and probably does experience quaking of some sort, with a wide variety of causes.
So no, Philosoraptor, the proper term would be a marsquake.