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 most violent shaking was felt in Aichi, according to official seismic assessments. — Yuri Kageyama, Los Angeles Times, 8 Nov. 2026

This was the type of seismic trade that happens only once a year across the NFL, if that. — Sean Hammond, Chicago Tribune, 7 Nov. 2026

The outcome represents a seismic shake-up in Maine, a blue state that has repeatedly elected Collins due to her independent streak. — David Sivak, The Washington Examiner, 4 Nov. 2026

Trump’s unpopularity is now seismic, and there’s a growing feeling that his movement is, after a decade of dominating the frontal lobe of the American mind, petering out. — Aidan McLaughlin, Vanity Fair, 4 Nov. 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)