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ber·​serk bər-ˈsərk How to pronounce berserk (audio)
-ˈzərk How to pronounce berserk (audio)
variants or berserker
bər-ˈsər-kər How to pronounce berserk (audio)
: an ancient Scandinavian warrior frenzied in battle and held to be invulnerable
: one whose actions are recklessly defiant


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: markedly out of control due to intense anger or excitement : frenzied
In this regular season, the 49ers won in Seattle, but lost to the Seahawks at Levi's [Stadium], which was packed with berserk fans.Scott Ostler
berserk adverb
The kids run berserk through the water slides and splash stations … Toby Rose
berserkly adverb
Still, after watching the berserkly funny documentary Starz Inside: Zombiemania, I've concluded I didn't know the half of it. Glenn Garvin

see also go berserk

Did you know?

Berserk comes from Old Norse berserkr, which combines ber- ("bear") and serkr ("shirt"). According to Norse legend, berserkrs were warriors who wore bearskin coverings and worked themselves into such frenzies during combat that they became immune to the effects of steel and fire. Berserk was borrowed into English (first as a noun and later as an adjective) in the 19th century, when interest in Scandinavian myth and history was high. It was considered a slang term at first, but it has since gained broader acceptance.

Examples of berserk in a Sentence

Recent Examples on the Web
There’s no evidence to suggest that the bear went berserk after overdosing, as the trailer, which went viral in December, shows. Michael O'Sullivan, Anchorage Daily News, 9 Feb. 2023 The word berserk exists in our dictionaries thanks to the Norse tales of these superhuman warriors. Stephen C. George, Discover Magazine, 21 Mar. 2022 The sort of wannabe cult action-comedy that gets off on its own displays of horrible behavior and listless set pieces, this Santa-goes-berserk story wants to be a new alt-holiday classic. David Fear, Rolling Stone, 1 Dec. 2022 In the first scene, a chimpanzee goes berserk on the set of a sitcom, a moment of absurd, bloody terror that becomes a motif and a thematic key. New York Times, 20 July 2022 Markets went berserk, there was a bond meltdown, and the country’s prime minister ultimately lost her job. Nicole Goodkind, CNN, 17 Nov. 2022 Throughout Friday’s game, both were on the bench in sweatsuits going berserk over big plays and celebrating teammates’ success. Chris Fedor, cleveland, 5 Nov. 2022 But — for reasons that can’t quite be explained — the film’s name and a tale of a twister sucking up sharks from the ocean and flinging them across Los Angeles went berserk on social media the night of its release on Syfy. Alex Ritman, The Hollywood Reporter, 1 Nov. 2022
In the past year, the real-estate market has, well, gone berserk. Alyssa Shelasky, Curbed, 16 Feb. 2022 But even that doesn’t seem to explain why some insist on the infallibility of AI, particularly since there are plenty of sci-fi films and TV shows that highlight AI that has gone berserk. Lance Eliot, Forbes, 2 May 2022 Mitch McConnell has gone predictably berserk over the prospect of increasing the inheritance tax by taxing capital gains at death. Timothy Noah, The New Republic, 18 June 2021 Besides equipment, the hunt for drugs has been equally berserk. Ananya Bhattacharya, Quartz, 4 May 2021 In the past few years, the disease had spread with a kind of berserk enthusiasm from Bradshaw’s prostate to his lungs and into his bone marrow. Katie Engelhart, The Atlantic, 2 Mar. 2021 Researchers have widely hypothesized that infectious agents—like viruses—trigger berserk immune responses in certain children with genetic predispositions. Beth Mole, Ars Technica, 14 May 2020 That is, these candidate vaccines seemed to prompt berserk immune responses that caused lung damage in monkeys and liver damage in ferrets. Beth Mole, Ars Technica, 1 May 2020 In some critically ill patients with COVID-19, berserk immune responses are thought to cause devastating damage to lungs and other organs. Beth Mole, Ars Technica, 10 Apr. 2020 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'berserk.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Noun and Adjective

Old Norse berserkr, probably from ber- bear + serkr shirt

First Known Use


1800, in the meaning defined at sense 1


1896, in the meaning defined above

Time Traveler
The first known use of berserk was in 1800

Dictionary Entries Near berserk

Cite this Entry

“Berserk.” Dictionary, Merriam-Webster, Accessed 25 Sep. 2023.

Kids Definition


1 of 2 adjective
ber·​serk bə(r)-ˈsərk How to pronounce berserk (audio) ˌbər- How to pronounce berserk (audio)
: gone out of control : crazy, amok
berserk adverb


2 of 2 noun
variants or berserker
: a Scandinavian warrior of ancient times who fought with great fury in battle and was believed impossible to kill or wound


from early Norse berserkr, from ber- (derived from the word for "bear") and serkr "shirt"

Word Origin
Many hundreds of years ago in what is now Scandinavia, certain warriors were known for their wild and savage behavior in battle. These fighters wore masks or garments of animal skin and the early Norse word for such a person was berserkr, meaning literally, "bear shirt." The word was borrowed into English in the early 19th century when many people became interested in Norse history and legend. From berserker, with the sense of "a Scandinavian warrior," the word became berserk, a general term for a person whose behavior is reckless and wild.

More from Merriam-Webster on berserk

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