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

What's especially remarkable is that the system can recreate the user's own voice, thanks to a voice cloning algorithm trained on recordings made before the onset of ALS. —Kurt Knutsson, FOXNews.com, 1 July 2025

Severe or repeated vomiting and sudden onset chest pain are two parts of what’s called the Mackler Triad, the trio of signs suggestive of Boerhaave syndrome. —Bruce Y. Lee, Forbes.com, 28 June 2025

The findings revealed that residents living closer to these investments — within 0.1 miles — experienced smaller declines in sleep efficiency and smaller increases in wakefulness after sleep onset compared to those living farther away. —Wendy Troxel, Baltimore Sun, 26 June 2025

Partly to blame is high inflation, claimed Bankrate, which has increased by about 24% since the onset of the pandemic in 2020. —Marco Quiroz-Gutierrez, Fortune, 24 June 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