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 outspoken late-night host criticized the SpaceX founder and controversial tech magnate as his company enters the stock market for the first time, a seismic move that made Musk the world's first trillionaire. —Edward Segarra, USA Today, 12 June 2026

That seismic decision came after Mayor Quinton Lucas sued to void the election results, arguing that the measure misled voters. —Kacen Bayless, Kansas City Star, 12 June 2026

Tenants who occupied the lower four floors are vacating, and a seismic upgrade will begin later this year. —Los Angeles Times, 12 June 2026

At one point in making the piece, the seismic feed itself became a problem. —Pablo Larios, Artforum, 10 June 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)