After-shock is a term used to describe the subsequent tremor that occurs following an earthquake. It's a significant event and can have serious consequences for affected communities. While aftershock is the most commonly used term, there are other synonyms that can also be used, including "second shock" and "tremor." Other variations may include "subsidence" or "earthquake aftershock." In essence, all of these synonyms refer to the same thing, which is the continuation of the shaking after the initial earthquake. It's important to note that aftershocks can continue for days, weeks, or even months after the initial event, making them a significant concern for people living in areas prone to earthquakes.