seismic

adjective

seis·​mic ˈsīz-mik How to pronounce seismic (audio)
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 How to pronounce seismic (audio)
adverb

Examples of seismic in a Sentence

Seismic social changes have occurred.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Around kickoff time, Sillie said, his cellphone texted a seismic alert. — Mery Mogollón, Los Angeles Times, 30 June 2026 The pandemic for me, as for many people, was like a seismic reorientation. — Angie Martoccio, Rolling Stone, 30 June 2026 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 However, either of those options would leave Houston one reliever short in a bullpen that just shouldered a seismic workload during this seven-game road trip. — Chandler Rome, New York Times, 29 June 2026 See All Example Sentences for seismic

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

Time Traveler
The first known use of seismic was in 1858

Phrases Containing seismic

Browse Nearby Words

seismetic
seismic
seismicity
See all Nearby Words

Cite this Entry

“Seismic.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/seismic. Accessed 7 Jul. 2026.

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Kids Definition

seismic

adjective
seis·​mic ˈsīz-mik How to pronounce seismic (audio)
ˈsīs-
: of, subject to, or caused by an earthquake or an earth vibration caused by something else (as an explosion)

More from Merriam-Webster on seismic

Nglish: Translation of seismic for Spanish Speakers

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