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

These include colorectal cancer and Lynch syndrome, a genetic condition linked to several cancers, particularly early-onset colorectal cancer. —Miriam Fauzia, Dallas Morning News, 19 Mar. 2026

For example, Blackstone acquired Hilton Hotels in 2007 in a deal valued at $26 billion, right before the onset of the global financial crisis. —Luisa Beltran, Sportico.com, 18 Mar. 2026

Traffic through the strait has plummeted since the onset of the Iran war, as Iranian attacks cause the largest oil supply disruption in history. —Josephine Rozzelle, CNBC, 17 Mar. 2026

In recent years, with the onset of more troubling and complexdoping sagas, WADA has gotten more involved in investigating doping allegations — a function that has largely been handled by the dozens of organizations that oversee the use of performance enhancers in certain countries and sports. —ABC News, 16 Mar. 2026

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