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

Her previous story had offered no reason to expect this seismic turn of events! —Han Ong, New Yorker, 15 Mar. 2026

Trier’s achievement is so seismic in Norway and its environs that it has been compared to the great Ingmar Bergman, who — hailing from Sweden, some 350 miles away — only achieved nine nominations in his entire lifetime. —Damon Wise, Deadline, 15 Mar. 2026

These finds indicate a once-bustling harbor complex that submerged due to environmental shifts, such as rising sea levels and seismic activity, Heritage Daily reported. —Maria Mocerino, Interesting Engineering, 14 Mar. 2026

Another year without capable play under center could have forced a seismic shakeup within the organization. —Jace Frederick, Twin Cities, 14 Mar. 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)