"movement or vibration of a part of the earth's crust," late 13c., eorthequakynge, from earth + quake (n.).
In this sense Old English had eorðdyn, eorðhrernes, eorðbeofung, eorðstyrung. Middle English also had terre-mote "earthquake" (late 14c.), from Old French terremote, from Latin terrae motus, from terra "earth" (see terra) + motus "a moving, motion," past participle of movere "to move" (see move (v.)).