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

Writing in his weekly economics update overnight, Mericle noted that the finance giant’s layoff tracker is now at a higher level than in 2019 at the onset of the pandemic. —Eleanor Pringle, Fortune, 11 Nov. 2025

Some of the most common symptoms of lung cancer include a persistent cough, chest pain, unexplained weight loss, shortness of breath and new onset wheezing, among others, according to the American Cancer Society. —Adrianna Rodriguez, USA Today, 10 Nov. 2025

Wind significantly increases heat loss, contributing to a faster onset of hypothermia, especially among children, the elderly, and individuals without adequate housing or heating. —Anna Skinner, MSNBC Newsweek, 10 Nov. 2025

Current understanding is that the benefits of HRT outweigh the potential risks when taken before age 60 or within 10 years of the onset of menopause. —Youri Benadjaoud, ABC News, 10 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