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Synonyms

onslaught

American  
[on-slawt, awn-] / ˈɒnˌslɔt, ˈɔn- /

noun

  1. an onset, assault, or attack, especially a vigorous one.


onslaught British  
/ ˈɒnˌslɔːt /

noun

  1. a violent attack

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of onslaught

1615–25; < Dutch aanslag a striking, (earlier) attack (equivalent to aan on + slag blow, stroke; akin to slay ), with assimilation to obsolete slaught slaughter

Explanation

Onslaught is a military term that refers to an attack against an enemy. It's safe to say that no one wants to be caught on the receiving end of an onslaught, because there will be lots of danger, destruction and probably death. One way to help you remember the brutal meaning of onslaught is through the word's English origin, slaught, meaning "slaughter." But onslaught can be used in non-military ways, too. It can mean a barrage of written or spoken communication, like an onslaught of emailed birthday wishes. Taken individually, the birthday wishes are nice but an onslaught is too many, too fast, all at once. Onslaught can also mean a sudden and severe start of trouble. For example, if your office is unprepared for the onslaught of flu season, the entire sales force will be home sick at the same time.

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Vocabulary lists containing onslaught

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

As the companies face an onslaught of liability claims, evidence and testimony heard in Kaley's case could be recalled in upcoming trials.

From BBC • Mar. 27, 2026

Season 2 returned nine years later to wrestle with Peak TV’s onslaught.

From Salon • Mar. 26, 2026

Iran, though severely weakened militarily and politically by an onslaught of airstrikes that began February 28, has voiced no intention to surrender.

From Barron's • Mar. 18, 2026

Curtis seemed to tense up amid the smooth onslaught.

From Los Angeles Times • Mar. 11, 2026

“Nothing withstands the onslaught of an angry Fflam!”

From "The Book of Three" by Lloyd Alexander