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

The two have met every other year since 2020, a byproduct of getting extra matchups beyond the usual inter-conference schedule this season and in 2022 thanks to the onset of the 17th game to the NFL regular-season schedule. — David Furones, Sun Sentinel, 19 Sep. 2026

The symptoms of the flu, caused by the influenza A or B virus, tend to come on very quickly, unlike the gradual onset of a cold or COVID-19. — Ann Sheehan, The Conversation, 18 Sep. 2026

Fed officials didn't begin raising interest rates from zero until March of that year, fully two years after the onset of Covid. — Kelly Evans, CNBC, 16 Sep. 2026

In his role as transportation correspondent since 2020, Benitez has covered aviation during the industry’s near-total collapse in the pandemic as well as space at the onset of America’s private space industry. — ABC News, 16 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