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

Even if Clinton and Gore benefited from headlines about a shrinking federal workforce, over time their effort looked more like sizzle than seismic change. —Jacob Bruggeman & Casey Eilbert / Made By History, TIME, 3 Mar. 2025

But unless there’s another delay or the threat of tariffs is completely dropped, the auto industry — and car prices — are set to experience a seismic shock. —Chris Isidore, CNN, 1 Mar. 2025

In the wake of the seismic political, legal and economic shocks that the Department of Governmental Efficiencies’ (DOGE) is wreaking on America, the work led by its unelected leader, Elon Musk is providing a global lesson in the importance of data ethics for government and business alike. —Lauren Coulman, Forbes, 28 Feb. 2025

Just last year, new excavations revealed the skeletons of two people who didn't die from the choking air or searing hot lava flows, but instead might be the first two ever found who died from the seismic activity accompanying the disaster. —Michael Franco, New Atlas, 28 Feb. 2025

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)