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

At the onset of Russia's full-scale war against Ukraine, Aliyev believed Moscow would win quickly and reestablish its dominance across the post-Soviet space. —Brendan Cole, MSNBC Newsweek, 25 July 2025

More than $10 million in cryptocurrency belonging to the Sinaloa cartel has been seized in Florida as part of nationwide drug raids since the onset of President Donald Trump’s second term, the Justice Department announced this week. —Greg Norman, FOXNews.com, 16 July 2025

Researchers have shown, in mice, that targeting these molecules with a vaccine can delay or prevent the onset of cancers. —Knowable Magazine, Smithsonian Magazine, 16 July 2025

He got released at the onset of free agency in March, visited the Pittsburgh Steelers, and ultimately agreed to return to the 49ers on a two-year contract. —Cam Inman, Mercury News, 12 July 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