onset

noun

on·​set ˈȯn-ˌset 

ˈän-

1

: attack, assault

withstand the onset of the army

2

: beginning, commencement

the onset of winter

the onset of age-related diseases

Synonyms

• attack
• onslaught
• raid
• assault
• strike
• attempt

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 the five years prior to the onset of the pandemic, the overall crime rate sat between 8 and 9.5 acts per 1,000 students. —Rebecca Noel, Charlotte Observer, 18 June 2025

Since then, city leaders added hundreds of new employees and, since the onset of the COVID pandemic, relied on one-time funding to balance the books. —Daniel Borenstein, Mercury News, 17 June 2025

In 2014, a study published in the Journal of the International Neuropsychological Society found crossword puzzles can help reduce the onset of dementia by two and a half years. —Jack Beresford, MSNBC Newsweek, 13 June 2025

The footage begins with the sun setting behind Earth's disk, heralding the onset of night aboard the ISS - the 45 minute period when the station passes through our planet's shadow. —Anthony Wood, Space.com, 12 June 2025

Word History

First Known Use

circa 1522, in the meaning defined at sense 1

Phrases Containing onset

• adult-onset diabetes
• juvenile-onset diabetes

Rhymes for onset

• abet
• asset
• baguette
• banquette
• barbette
• beget
• beset
• brevet
• briquette
• brunet
• brunette
• burette

Kids Definition

onset

noun

on·​set ˈȯn-ˌset 

ˈän-

1

: attack entry 2 sense 1

2

: beginning sense 1

Medical Definition

onset

noun

on·​set ˈȯn-ˌset, ˈän- 

: the initial existence or symptoms of a disease

the onset of scarlet fever