seismic

adjective

seis·​mic ˈsīz-mik 

ˈsīs-

1

: of, subject to, or caused by an earthquake

also : of or relating to an earth vibration caused by something else (such as an explosion or the impact of a meteorite)

2

: of or relating to a vibration on a celestial body (such as the moon) comparable to a seismic event on earth

3

: having a strong or widespread impact : earthshaking

seismic social changes

seismically

ˈsīz-mi-k(ə-)lē 

adverb

Examples of seismic in a Sentence

Seismic social changes have occurred.

Recent Examples on the Web

Proponents argue the current library is too small to meet the city’s needs and requires seismic upgrades. —Sierra Lopez, Mercury News, 14 May 2026

Lawmakers have said that this year’s measures are not the end of their interest in regulating an enormous and still-emerging technology, the effects of which may have seismic effects across Coloradans’ social, personal and professional lives. —Seth Klamann, Denver Post, 14 May 2026

Four similar seismic signatures were registered at that exact time, in that approximate area, the pattern of which resembled underwater mines or overground quarry blasts, the Spanish National Seismic Network told CNN. —Pau Mosquera, CNN Money, 12 May 2026

Some systems detect the seismic impact of people dropping to the ground, Price said. —Mead Gruver, Los Angeles Times, 12 May 2026

Word History

Etymology

Greek seismos shock, earthquake, from seiein to shake; probably akin to Avestan thwaēshō fear

First Known Use

1858, in the meaning defined at sense 1

Phrases Containing seismic

• seismic shift

Kids Definition

seismic

adjective

seis·​mic ˈsīz-mik 

ˈsīs-

: of, subject to, or caused by an earthquake or an earth vibration caused by something else (as an explosion)