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

This association was partially mediated by differences in body weight throughout childhood, with childhood obesity linked to early pubertal onset. —Maria Morava, MSNBC Newsweek, 18 Aug. 2025

Despite the uncertainty, the Trump White House is confident that the onset of his broad tariffs will provide clarity about the path of the world’s largest economy. —Josh Boak, Chicago Tribune, 7 Aug. 2025

Some studies have found micro-particles of zinc in FFA patients’ hair follicles, suggesting sunscreen could be part of the onset. —Ashley Abramson, Allure, 4 Aug. 2025

Mortgage rates are certainly a factor among buyers when deciding to make an offer, and home prices are also up more than 50% since the onset of the pandemic, according to the U.S. Case-Shiller Home Price Index. —Sydney Lake, Fortune, 31 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