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

Fasten loose objects or shelter objects in a safe location prior to the onset of winds. —Ca Weather Bot, Sacbee.com, 24 Dec. 2025

For this outbreak, the illness reporting period is 15 to 32 days after illness onset. —Ingrid Vasquez, PEOPLE, 24 Dec. 2025

Bullion neared $4,500 an ounce Tuesday, more than double since 2022 — a year when both Russia’s invasion of Ukraine shattered a period of relative geopolitical calm and the onset of inflation eroded investors’ trust in government currencies. —Liz Hoffman, semafor.com, 23 Dec. 2025

Falling back into the lower atmosphere, the crew was warned to get back in their seats to strap in before the onset of atmospheric deceleration. —William Harwood, CBS News, 20 Dec. 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