/errth"kwayk'/ , n.
1. a series of vibrations induced in the earth's crust by the abrupt rupture and rebound of rocks in which elastic strain has been slowly accumulating.
2. something that is severely disruptive; upheaval.
[ 1300-50; ME erthequake (see EARTH, QUAKE), r. OE eorthdyne (see DIN) ]
Syn. 1. quake, tremor, shock, seism, temblor.