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 of onset

• attack
• assault
• onslaught
• raid
• offensive
• aggression
• offense
• 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

Things hummed along for years until the onset of the COVID-19 pandemic in 2020. —Alexandra Kirkman, Fortune, 25 Nov. 2025

The occasion for the trip was Craig’s recent diagnosis with early-onset Alzheimer’s. —Jake Kanter, Deadline, 25 Nov. 2025

The end of the decade would herald the onset of his first imperial period as an in demand star of international renown. —Ryan Coleman, Entertainment Weekly, 24 Nov. 2025

It was found that hydroxide ions shifted the absorption onset to energies different from those in pure ice. —Mrigakshi Dixit, Interesting Engineering, 21 Nov. 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