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

Since the onset of the Covid-19 pandemic these swipe fees have increased nearly 70%, according to NACS, which cited data from Nilson. —Gordon Ebanks, CNN Money, 19 Oct. 2025

Her mother died in this house in 2020 due to early-onset Alzheimer's after living here with her father, Gerry Grubbs, for about 15 years, DesRochers tells me. —Grace Tucker, Cincinnati Enquirer, 18 Oct. 2025

Keep one notebook for every conversation with doctors, questions for medical staff, caseworkers, medication changes, medical appointments, onset of new symptoms, etc. —Kat McGowan, NPR, 18 Oct. 2025

However, onset of cooler temperatures and rain could still enhance fall color, Schneider pointed out. —Jim Higgins, jsonline.com, 17 Oct. 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