quake (v.)

Old English cwacian "quake, tremble, chatter (of teeth)," related to cweccan "to shake, swing, move, vibrate," of unknown origin with no certain cognates outside English. Perhaps somehow imitative. In reference to earth tremors, probably by c. 1200. Related: Quaked; quaking.

early 14c., "a trembling in fear," from quake (v.). Rare except in combinations. Now usually as a shortening of earthquake, in which use it is attested from 1640s. Old English had the verbal noun cwacung "shaking, trembling."