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

The Timberwolves do not want to make a seismic change to a roster that advanced to the Western Conference finals if Durant is not on board with the move, team sources said. —Jon Krawczynski, New York Times, 17 June 2025

But the college hockey landscape felt another seismic event in November. —Corey Masisak, Denver Post, 15 June 2025

The effect of Netflix’s Drive To Survive on Formula 1 was seismic. —Kanzah Maktoum, Forbes.com, 15 June 2025

The vote marked a seismic moment for the Kansas City region, signifying a major retaliatory shot from Missouri amid an attempt by Kansas to lure the teams across State Line Road. —Kacen Bayless, Kansas City Star, 11 June 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)