Synonyms of onset

onset

noun

ˈȯn-ˌset 

1

as in attack

the act or action of setting upon with force or violence

the walls withstood the onset of the first battalion

Synonyms & Similar Words

• attack
• assault
• onslaught
• raid
• offensive
• aggression
• offense
• strike
• attempt
• bombardment
• rush
• blitzkrieg
• invasion
• blitz
• incursion
• descent
• coup de main
• charge
• counterattack
• barrage
• ambush
• bombing
• siege
• breakthrough
• counteroffensive
• envelopment
• ambuscade
• foray
• sortie
• storm
• air raid
• counteraggression
• volley
• sally
• sack
• pillage
• counterassault
• salvo
• counterstrike
• hail
• flanking
• fusillade
• ravage
• cannonade
• whammy

Antonyms & Near Antonyms

• defense
• resistance
• opposition
• guard
• protection
• security
• shield
• defensive
• shelter

2

as in beginning

the point at which something begins

the claim that if you take enough vitamin C at the onset of a cold, you'll often recover faster

Synonyms & Similar Words

• beginning
• start
• inception
• commencement
• alpha
• launch
• dawn
• genesis
• outset
• baseline
• birth
• threshold
• infancy
• morning
• initiation
• incipience
• kickoff
• incipiency
• nascence
• day one
• inauguration
• origination
• nascency
• origin
• get-go
• arrival
• founding
• emergence
• first base
• spring
• dawning
• creation
• advent
• opening
• childhood
• drawing board
• ground zero
• germ
• institution
• debut
• source
• well
• appearance
• cradle
• square one
• fountain
• root
• youth
• seedbed
• fountainhead
• wellspring

Antonyms & Near Antonyms

• end
• conclusion
• ending
• period
• close
• completion
• cessation
• termination
• closing
• closure
• finish
• stop
• omega
• finale
• windup

Example Sentences

Recent Examples of onset

Now, eight years and nearly two full terms later, the governor has paused those incentives as the onset of data centers has stressed energy and water resources and public opinion has swiftly turned against the tech behemoths. — Ben Szalinski, Chicago Tribune, 18 Aug. 2026

Postpartum psychosis is a rare but serious medical emergency characterized by severe, rapid onset psychiatric episodes such as mania, depression, delusions or hallucinations. — Peter Charalambous, ABC News, 17 Aug. 2026

So nearly half a decade after the onset of the Ukraine War, the Western launch market has not changed much. — Eric Berger, ArsTechnica, 17 Aug. 2026

The couple quietly eloped the following year, before the onset of the COVID-19 pandemic, the actress confirmed in 2022. — Ryan Coleman, Entertainment Weekly, 16 Aug. 2026