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

An index of consumer confidence fell in April to its lowest level since the onset of the pandemic. —Scott Horsley, NPR, 2 May 2025

The Conference Board, a business group, reported Tuesday that Americans’ confidence in the economy fell for the fifth straight month to the lowest level since the onset of the COVID-19 pandemic. —Paul Wiseman, Los Angeles Times, 2 May 2025

Lucy Nicholson | Reuters McDonald’s on Thursday reported mixed quarterly results as its U.S. same-store sales fell for the second straight quarter, posting their largest domestic decline since the onset of the Covid pandemic. —Amelia Lucas, CNBC, 1 May 2025

Your parent developed Alzheimer’s at the same age Age of symptom onset tends to be consistent within families. —Angela Haupt, Time, 25 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