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

Each crane also required 10 custom connections to the building, engineered to meet local seismic requirements. — Kaif Shaikh, Interesting Engineering, 24 Oct. 2026

Since then, however, Amazon has dropped more than 7%, with an up-and-down chart over the past month looking more like seismic activity than stock trading. — Zev Fima, CNBC, 20 Oct. 2026

The Chiefs at least discussed, even if briefly, that sort of seismic change. — Sam McDowell 16, Kansas City Star, 16 Oct. 2026

Why did the songs still feel seismic even with such relatively low mainstream profiles? — Andrew Unterberger, Billboard, 15 Oct. 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)