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 Cox remarks, a minority of attendees loudly booed his presence, but the governor was able to rally applause by invoking his pleasure to be back at his alma mater. —Alex J. Rouhandeh, MSNBC Newsweek, 1 Oct. 2025

August saw a revival of sorts before the onset of fall witnessed more stagnation. —Naman Ramachandran, Variety, 27 Sep. 2025

Her first donation went to the Association for Frontotemporal Degeneration (AFTD), which supports research, education and family resources for those affected by the early-onset dementia. —Deirdre Bardolf, FOXNews.com, 27 Sep. 2025

To break that cycle, please give therapy another try, this time with a therapist specifically trained to work with gay men, preferably gay men who lived through the onset of the AIDS crisis. —R. Eric Thomas, Mercury News, 27 Sep. 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