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

In any case, theatrical releases or (re-releases) of popular TV shows are all gravy for cinema operators, who are enjoying the biggest year at the box office since the onset of the pandemic. — Rebecca Rubin, Variety, 8 Nov. 2026

Treatment questions People in the circadian group reported an earlier onset of depression and more severe symptoms than those who did not meet the criteria. — Deirdre Bardolf, FOXNews.com, 7 Nov. 2026

Participants took part in video calls each week, discussing everything from healthy eating to physical activity in relation to preventing the onset of type 2 diabetes. — New Atlas, 7 Nov. 2026

While both early- and late-onset Alzheimer's are characterized by the buildup of amyloid plaques and tau tangles, the new findings suggest that tau pathology may be especially aggressive in younger patients. — Daniella Gray, MSNBC Newsweek, 6 Nov. 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