- A sudden movement of the earth's crust caused by the release of stress accumulated along geologic faults or by volcanic activity.
- A movement or vibration of a part of the earth's crust.
- Like, or characteristic of, an earthquake; loud; startling.
- A shaking, trembling, or concussion of the earth, due to subterranean causes, often accompanied by a rumbling noise. The wave of shock sometimes traverses half a hemisphere, destroying cities and many thousand lives; -- called also <altname>earthdin</altname>, <altname>earthquave</altname>, and <altname>earthshock</altname>.
- a bell signal constructed to operate on the theory that a few seconds before the occurrence of an earthquake the magnet temporarily loses its power.
- a disturbance that is extremely disruptive
- shaking and vibration at the surface of the earth resulting from underground movement along a fault plane of from volcanic activity