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

• aggression
• assault
• attack
• attempt
• blitz
• blitzkrieg
• charge
• coup de main
• descent
• offense
• offence
• offensive
• onslaught
• raid
• rush
• 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

More importantly, failing to articulate an acceptable mistake at the onset will leave your team without the language to define which levers were most important to drive business goals. —Rebecca Shaddix, Forbes.com, 8 Apr. 2025

Measles rash appears three to five days after the onset of the first symptoms. —USA Today, 7 Apr. 2025

For example, in 2020, markets saw their second-worst day of the year on March 12 at the onset of the Covid pandemic. —Lorie Konish, CNBC, 7 Apr. 2025

However, consumers should be mindful of dosage and onset time, which can vary based on metabolism. —Matt Rozo, Mercury News, 4 Apr. 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