onset

noun on·set \ ˈȯn-ˌset , 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

See onset defined for English-language learners

See onset defined for kids

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 of onset from the Web

The damage described increases his chances for early onset of arthritis, which could affect his career longevity down the road.

— profootballdoc, sandiegouniontribune.com, "Dalvin Cook ACL tear (and more) confirmed," 2 Oct. 2017
But with the onset of dry, cool weather comes a fresh new set of skin and makeup challenges, involving more than a few pesky flakes, spots of redness and hard to cover dry patches.

— jenna rennert, Vogue, "The Only 5 Beauty Essentials You Need in Your Makeup Bag," 30 Oct. 2017
If it's left untreated, the plague can be fatal within 18 to 24 hours of the disease's onset.

— heather leighton, Houston Chronicle, "Nine countries have issued health warnings for the plague," 26 Oct. 2017
With refinement, however, Baud believes the device will be able to detect abnormal brain activity caused by conditions like early onset sepsis, an infection of the bloodstream that can cause brain damage.

— emily underwood, Science | AAAS, "Ultrasonic probe could detect stroke, brain damage in young babies," 11 Oct. 2017
After independence and the onset of military rule in 1962, General Ne Win booted out hundreds of thousands of South Asians, and the junta began to adopt policies that persecuted the Rohingya.

— joe freeman, The Atlantic, "The 'Good Monk' Myth," 29 Sep. 2017
If Florida State–Miami had not been bumped to Oct. 7 by the onset of Hurricane Irma, Week 3 would feature rematches of three games that tell important chapters of the past two decades of college football history.

— the si staff, SI.com, "Week 3 Picks: Who Prevails in Clemson vs. Louisville and Texas vs. USC?," 14 Sep. 2017
The new estimate of the rate of carbon release at the PETM onset is similar to that found in 2011 by a team led by Pennsylvania State University.

— dominik butzmann, National Geographic, "Earth Hasn’t Heated Up This Fast Since the Dinosaurs’ End," 21 Mar. 2016
After recommending her mother see a doctor, Diana was diagnosed with early-onset Alzheimer’s, becoming one of the five to 10 percent of people who are identified with the fatal degenerative disease before 65.

— michele parente, sandiegouniontribune.com, "Taking a walk for her mother, taking steps to cure Alzheimer's," 6 Oct. 2017

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.