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

• aggression
• assault
• attack
• attempt
• blitz
• blitzkrieg
• charge
• coup de main
• descent
• offense
• offence
• offensive
• onslaught
• raid
• rush
• 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

Exposure to air pollution such as wildfire smoke can also lead to the onset of asthma in otherwise healthy people, Lamb said. —Karen Garcia, Los Angeles Times, 15 Jan. 2025

Chronic stress disproportionately impacts Black women and is a major contributor to the onset of serious health conditions. —Jameelah Nasheed, Essence, 13 Jan. 2025

But those deaths began to rise again in 2019 and shot up during the onset of the COVID-19 pandemic, according to data from the Centers for Disease Control and Prevention (CDC). —Joseph Choi, The Hill, 10 Jan. 2025

For women, however, the most dramatic shift occurs with the onset of perimenopause and menopause, when falling estrogen levels lead to a sharp decline in collagen. —Eva Crouse, Flow Space, 6 Jan. 2025

Word History

First Known Use

circa 1522, in the meaning defined at sense 1

Phrases Containing onset

• adult-onset diabetes
• juvenile-onset diabetes

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