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

Unfortunately, the building also needs to undergo seismic retrofitting, so until that’s completed, the frescoes must remain beneath the paint that has kept them hidden for nearly a century. —The Editors Of Artnews, ARTnews.com, 26 Mar. 2025

Now, Waltz, who represented northeast Florida in Congress, is at the center of mounting questions about a seismic intelligence failure that placed secret pending military operations at risk and might have exposed highly sensitive information to foreign intelligence adversaries. —David Catanese, Miami Herald, 25 Mar. 2025

The InSight lander, launched in 2018, was designed to measure the planet’s internal activity, including its temperature, seismic waves, and core dynamics. —Victoria Corless, Space.com, 21 Mar. 2025

The last time the program advanced to the semis was in 2022, when an unprecedented spring showdown with North Carolina (and what turned out to be Mike Krzyzewski’s last game) scared up a seismic 18.5 million viewers. —Anthony Crupi, Sportico.com, 21 Mar. 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)