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

In order to access the fund, utilities would have to earn a first-of-its-kind annual safety certification before the onset of wildfire season. Taryn Luna, latimes.com, "Utility customers will pay $10.5 billion for California wildfire costs under bill sent to Newsom," 11 July 2019 Collier was just 62 when she was diagnosed with early-onset Alzheimer’s in 2014. courant.com, "Community News For The Colchester Edition," 5 July 2019 McKenzie, a veteran of combat in Iraq and Afghanistan, took command of Central Command in late March, shortly before the onset of the latest surge in tensions with Iran. Washington Post, "US commander says Mideast buildup prompted Iran ‘step back’," 7 June 2019 Over time, one part of the fuzzy picture came into focus: The mysterious linear resistivity that Bednorz and Müller observed in their first cuprate kept showing up in other cuprates and materials before the onset of superconductivity. Quanta Magazine, "Universal Quantum Phenomenon Found in Strange Metals," 19 Nov. 2018 Before the onset of the 2008 crash, for example, price stability was thought to be a fair proxy for financial stability. Kevin Warsh, WSJ, "The Fault Lies in R-Star and in Ourselves," 25 Sep. 2018 And at the onset of the trial, defense attorneys suggested a new theory: The blaze was ignited by a band of arsonists. Matthias Gafni, SFChronicle.com, "Ghost Ship defendant Max Harris testifies: ‘There weren’t hard and fast rules’," 17 June 2019 The onset of spring has welcomed a new batch of body shimmers to the bunch. Maya Allen, Marie Claire, "The 5 Best Body Oils For the Ultimate Summer Glow-Up," 6 June 2019 The average onset for most psychiatric disorders dovetails with late high school and early college, a period fraught with change and stress. Julia Sclafani, latimes.com, "National, local mental health experts offer perspective on youth suicide epidemic at Aliso Viejo forum," 6 June 2019

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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Statistics for onset

Last Updated

15 Jul 2019

Look-up Popularity

Time Traveler for onset

The first known use of onset was circa 1522

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More Definitions for onset



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

Rhyming Dictionary: Words that rhyme with onset

Thesaurus: All synonyms and antonyms for onset

Spanish Central: Translation of onset

Nglish: Translation of onset for Spanish Speakers

Britannica English: Translation of onset for Arabic Speakers

Comments on onset

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food or victuals

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