on·​set | \ ˈȯn-ˌset How to pronounce onset (audio) , ˈän- \

Definition of onset

1 : attack, assault withstand the onset of the army
2 : beginning, commencement the onset of winter the onset of age-related diseases

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Examples of onset in a Sentence

the walls withstood the onset of the first battalion the claim that if you take enough vitamin C at the onset of a cold, you'll often recover faster
Recent Examples on the Web The state is now reporting that the onset of symptoms was as early as January for seven cases. Rich Exner, cleveland, "Mapping Ohio’s 26,954 coronavirus cases, updates, trends," 15 May 2020 Cuomo warns of possible second or third wave Cuomo said the initial onset of coronavirus may just be its first wave, echoing a warning from Dr. Robert Redfield, the director of the Centers for Disease Control and Prevention. CBS News, "Cuomo says Michael Bloomberg is helping New York launch testing and tracing program," 22 Apr. 2020 That the examples stop before the Ukraine affair that led to his impeachment, let alone the onset of the coronavirus crisis, is unfortunate, but of course no fault of Drezner’s. Gabriel Debenedetti, New York Times, "Three Views of Donald Trump," 17 Apr. 2020 Complicating matters is the onset of mysterious swarms—similar to dust storms, only composed of what appear to be tiny robots. Jennifer Ouellette, Ars Technica, "Rocinante crew ventures into worlds beyond the Ring in The Expanse S4 trailer," 18 Nov. 2019 Both of these forms of cancer are most likely to show up after menopause, the Mayo Clinic says, the average onset of which is 51. Erika Stallings, SELF, "Why Are Uterine Cancer Rates Rising So Drastically in Black Women?," 6 Nov. 2019 The onset of partial oligarchy is in fact a phase transition for another model of economic transactions, as first described in 2000 by physicists Jean-Philippe Bouchaud, now at École Polytechnique, and Marc Mézard of the École Normale Supérieure. Bruce M. Boghosian, Scientific American, "Is Inequality Inevitable?," 1 Nov. 2019 In less than ten minutes, the onset would be complete; her Affinity would be gone. David Canfield, EW.com, "Read an excerpt from Blood Heir, the year's most controversial YA novel," 17 Oct. 2019 In Kenya, the locust maturation is coinciding with the onset of the rainy season. Neha Wadekar, Quartz Africa, "Two new generations of locusts are set to descend on East Africa again—400 times stronger," 10 Apr. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'onset.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of onset

circa 1522, in the meaning defined at sense 1

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Time Traveler for onset

Time Traveler

The first known use of onset was circa 1522

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Statistics for onset

Last Updated

19 May 2020

Cite this Entry

“Onset.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/onset. Accessed 25 May. 2020.

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More Definitions for onset


How to pronounce onset (audio)

English Language Learners Definition of onset

: the beginning of something


on·​set | \ ˈȯn-ˌset How to pronounce onset (audio) , ˈän- \

Kids Definition of onset

1 : beginning sense 1 the onset of winter


on·​set | \ ˈȯn-ˌset, ˈän- How to pronounce onset (audio) \

Medical Definition of onset

: the initial existence or symptoms of a disease the onset of scarlet fever

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More from Merriam-Webster on onset

Thesaurus: All synonyms and antonyms for onset

Rhyming Dictionary: Words that rhyme with onset

Spanish Central: Translation of onset

Nglish: Translation of onset for Spanish Speakers

Britannica English: Translation of onset for Arabic Speakers

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