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 of onset

• attack
• assault
• onslaught
• raid
• offensive
• aggression
• offense
• strike

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

Mayfield served as an advisor at the onset of her campaign and helped bring on some of the people who currently serve on her campaign. — Miami Herald, 25 Sep. 2026

The onset of rot is creeping closer and the meat may even begin to stink. — Jack Hennessy, Outdoor Life, 23 Sep. 2026

For example, during the onset of the Iran war earlier this year, the platform recorded a 450% increase in clicks on Oman’s visa application as travelers sought alternative destinations and evacuation routes. — Cnt Editors, Condé Nast Traveler, 22 Sep. 2026

Green Bay Packers’ all-time leading rusher Ahman Green, who recently announced his diagnosis with early-onset Parkinson’s disease, will get the Matthew Thomas Robinson Courage Award. — Angelique Jackson, Variety, 21 Sep. 2026

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
• binet
• 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