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

At the onset, $50 million in seed money was allocated statewide, but the law stated an additional unspecified amount would be needed in the future. —Howard Blume, Los Angeles Times, 13 May 2025

Former Grey’s Anatomy star Patrick Dempsey is returning to broadcast TV as the lead in Memory of a Killer, Fox’s straight-to-series thriller about a hitman who develops early onset Alzheimer’s. —Nellie Andreeva, Deadline, 12 May 2025

Melatonin supplementation has been shown to improve sleep onset and quality. —Sarah Jividen, Verywell Health, 9 May 2025

But Corrado can do little to slow the onset of Giuliana’s psychic collapse. —Samantha Bergeson, IndieWire, 6 May 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