foreshock

[ fawr-shok, fohr- ]
/ ˈfɔrˌʃɒk, ˈfoʊr- /

noun Geology.

a relatively small earthquake that precedes a greater one by a few days or weeks and originates at or near the focus of the larger earthquake.

Origin of foreshock

First recorded in 1900–05; fore- + shock1

British Dictionary definitions for foreshock

foreshock
/ (ˈfɔːˌʃɒk) /

noun

a relatively small earthquake heralding the arrival of a much larger one. Some large earthquakes are preceded by a series of foreshocks Compare aftershock