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 of the first two offseasons under Chisholm’s new ownership regime have been defined by seismic roster change. — Zack Cox, Boston Herald, 6 July 2026

Rosenqvist’s departure was a bit of a shock, but Scott Dixon decision to leave Chip Ganassi Racing after 25 years with the team was of seismic proportions. — Bruce Martin, Forbes.com, 4 July 2026

Researchers estimate that an event of similar magnitude has an average return period of about 180 years, based on Venezuela’s seismic hazard profile. — Antonio María Delgado, Miami Herald, 3 July 2026

During the huge Round of 32 knockout showdown, packed crowds inside the legendary Estadio Azteca generated enough ground movement to trigger local seismic monitoring equipment. — Alejandro Avila Outkick, FOXNews.com, 2 July 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)