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

Victims spoke of the onset of anxiety, panic attacks, depression and PTSD following the incident. —Alyssa Goldberg, USA Today, 26 Mar. 2026

That was a team goal at the season’s onset, sophomore wing Tori McKinney said Thursday, but that doesn’t mean Gophers are simply happy to be here. —John Shipley, Twin Cities, 26 Mar. 2026

Before the onset of the war, inflation was on a downward path and the global economy was growing at a faster pace than forecast in December. —Mustafa Qadri, CNN Money, 26 Mar. 2026

These are the chapters that feature the merry trickster of the forest, Tom Bombadil, a classic fiddle-dee-dee-mischief type who waylays the hobbits at the onset of their quest. —Rebecca Alter, Vulture, 25 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