sudden

1 of 2

adjective

sud·​den ˈsə-dᵊn 

1

a

: happening or coming unexpectedly

a sudden shower

b

: changing angle or character all at once

a sudden drop in the ocean bottom

2

: marked by or manifesting abruptness or haste

a sudden departure

3

: made or brought about in a short time : prompt

suddenly adverb

suddenness

ˈsə-dᵊn-(n)əs 

noun

sudden

2 of 2

noun

obsolete

: an unexpected occurrence : emergency

Phrases

all of a sudden or less commonly on a sudden

: very quickly in usually an unexpected way : in a sudden manner

Synonyms

Adjective

• abrupt
• unanticipated
• unexpected
• unforeseen
• unlooked-for

Choose the Right Synonym for sudden

precipitate, headlong, abrupt, impetuous, sudden mean showing undue haste or unexpectedness.

precipitate stresses lack of due deliberation and implies prematureness of action.

the army's precipitate withdrawal

headlong stresses rashness and lack of forethought.

a headlong flight from arrest

abrupt stresses curtness and a lack of warning or ceremony.

an abrupt refusal

impetuous stresses extreme impatience or impulsiveness.

an impetuous lover proposing marriage

sudden stresses unexpectedness and sharpness or violence of action.

flew into a sudden rage

Examples of sudden in a Sentence

Adjective

a sudden change in temperature

Sudden fame can be difficult to deal with.

She had a sudden urge to be outside.

His death was very sudden.

a sudden turn in the road

I was surprised by her sudden decision to quit.

The director's sudden departure leaves the organization's future uncertain.

Recent Examples on the Web

Adjective

In that light, the sudden uptick in volatility is not a surprise. —Jim Edwards, Fortune, 18 June 2025

Medical emergencies can also lead to sudden itinerary changes. —David Nikel, Forbes.com, 18 June 2025

Research suggests Lyme can cause sudden vision loss, damage to the optic nerve, and neurotrophic keratitis (decreased corneal sensation). —Angela Haupt, Time, 18 June 2025

Of course, even with a sudden influx of stud prospects joining the lineup, the Red Sox could continue to build around him, too. —Eno Sarris, New York Times, 18 June 2025

Word History

Etymology

Adjective

Middle English sodain, from Anglo-French sudain, from Latin subitaneus, from subitus sudden, from past participle of subire to come up, from sub- up + ire to go — more at sub-, issue entry 1

First Known Use

Adjective

14th century, in the meaning defined at sense 1a

Noun

1558, in the meaning defined above

Phrases Containing sudden

• all of a sudden
• on a sudden
• sudden death
• sudden infant death syndrome
• sudden victory

Video

'All over sudden' vs. 'All of a sudden'

Figuring it out at once

Kids Definition

sudden

adjective

sud·​den

ˈsəd-ᵊn

1

a

: happening or coming unexpectedly

a sudden shower

b

: changing angle or character all at once

a sudden turn in the road

2

: marked by or showing haste

a sudden decision

3

: made or brought about in a short time

a sudden cure

suddenly adverb

suddenness

ˈsəd-ᵊn-(n)əs

noun