1. an instance of agitation of the earth's crust; - Example: "the first shock of the earthquake came shortly after noon while workers were at lunch" [syn: shock, seismic disturbance]
WordNet (r) 3.0 (2006):
seismic disturbance
n 1: an instance of agitation of the earth's crust; "the first
shock of the earthquake came shortly after noon while
workers were at lunch" [syn: shock, seismic
disturbance]