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

Just when the world seems to have caught on to the duanju craze, Chinese companies are midway through another seismic change. —Chang Che, New Yorker, 25 Apr. 2026

This is hardly the first seismic change for NASCAR this year. —Ryan Morik, FOXNews.com, 24 Apr. 2026

Ahead of Hamilton’s potentially seismic decision, The Star spoke with political experts, supporters, skeptics and his own campaign team about whether the founding pastor, who often tries to convey nuance in politics, can convert his personal popularity and brand into votes. —Kacen Bayless, Kansas City Star, 24 Apr. 2026

The seismic swarm only happened after the magma had almost reached the surface. —Robin George Andrews, Scientific American, 23 Apr. 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)