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

But by 2016, stickers replaced handwriting as mobile ordering grew more popular, and the practice completely disappeared in 2020 with the onset of the Covid-19 pandemic. —Amelia Lucas, CNBC, 9 Sep. 2025

Their proportion of global leader travel fell from around 15% in 1990-1994 to about 10% since the onset of the COVID-19 pandemic in 2020. —Collin J. Meisel, The Conversation, 9 Sep. 2025

What’s really happening, of course, is a sudden onset of Tourette’s, presumably exacerbated by mounting stress both at home and at school. —Kate Erbland, IndieWire, 7 Sep. 2025

Genetic tests revealed the cause, early-onset FSHD, which only affects 5-10% of those with the disease. —Kate Wolffe, Sacbee.com, 7 Sep. 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