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

The onset of bye weeks negatively impacts affected players, but evens out over course of season. —Greg Cote october 7, Miami Herald, 7 Oct. 2025

The dry and breezy weather system is forecast to persist through the afternoon and is expected to weaken only with the onset of evening, as wind gusts diminish and relative humidity increases. —Anna Skinner, MSNBC Newsweek, 6 Oct. 2025

Days earlier, at the onset of lockdown, Jiang tried to break out of the hotel and was beaten up by the guards, who later apologized to him profusely. —Yangyang Cheng, NPR, 4 Oct. 2025

Due to Andrea Swift's health, Taylor decided not to go on a large tour for her seventh album, and then the smaller Lover Fest was canceled in 2020 with the onset of the pandemic. —Janey Tracey, Entertainment Weekly, 2 Oct. 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