accident

noun

ac·​ci·​dent ˈak-sə-dənt  -ˌdent 

ˈaks-dənt

1

a

: an unforeseen and unplanned event or circumstance

Their meeting was an accident.

b

: lack of intention or necessity : chance

They met by accident rather than by design.

2

a

: an unfortunate event resulting especially from carelessness or ignorance

was involved in a traffic accident

b

medical : an unexpected and medically important bodily event especially when injurious

a cerebrovascular accident

c

law : an unexpected happening causing loss or injury which is not due to any fault or misconduct on the part of the person injured but for which legal relief may be sought

d

US, informal

—used euphemistically to refer to an uncontrolled or involuntary act or instance of urination or defecation (as by a baby or a pet)

The puppy had an accident on the rug.

3

: a nonessential property or quality of an entity or circumstance

the accident of nationality

Frequently Asked Questions

What is the difference between accidental and incidental?

Accidental describes what was not planned or intended. It means "happening by accident" or "happening as an accident," as in "an accidental discovery" and "an accidental injury." Incidental typically means "happening as a minor part or result of something else," as in "a chapter that is incidental to the novel's plot." For more information read the full article.

Do you say 'on accident' or 'by accident'?

While both "by accident" and "on accident" are used, "by accident" is far more common.

What does 'accident waiting to happen' mean?

The phrase "an accident waiting to happen" refers to a person or thing that is dangerous or unsafe. For example, a very clumsy person and a rickety ladder might both be referred to as "an accident waiting to happen."

Synonyms of accident

• casualty
• disaster
• catastrophe
• mishap
• tragedy

Examples of accident in a Sentence

He was injured in an accident at work.

The accident happened when her car slid on a patch of ice.

Investigators are still trying to determine the cause of the accident.

Their meeting was an accident.

Recent Examples on the Web

Typically, accidents happen around takeoff or landing, according to Gorwitz, such as the Amazon cargo plane that skidded of the end of the runway in September at Miami International Airport, killing five people. — Sofia Saric, Miami Herald, 2 Nov. 2026

But service reliability doesn’t happen by accident or by delaying projects and investments. — H. Russell Frisby, Baltimore Sun, 2 Nov. 2026

According to a police accident report from Saturday night’s fatality, witnesses told police that a vehicle traveling westbound on County Road 250 South reportedly disregarded a stop sign and struck Schultz’s vehicle, which overturned. — Post-Tribune, Chicago Tribune, 2 Nov. 2026

Its accident-and-illness plan covers prescription food, behavioral treatment and microchipping. — Matt Richardson, CBS News, 2 Nov. 2026

Word History

Etymology

Middle English, "happening, nonessential property, diseased condition, disturbance (of the mind)," borrowed from Anglo-French, "irregularity, incident, symptom," borrowed from Latin accident-, accidens "chance event, contingent attribute" (translating Greek symbebēkós), from present participle of accidere "to fall down, impinge on, be heard, happen," from ad- ad- + cadere "to fall" — more at chance entry 1

First Known Use

14th century, in the meaning defined at sense 3

Phrases Containing accident

• accident insurance
• accident of birth
• accident of nature
• accident-prone
• cerebrovascular accident
• industrial accident
• no accident

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Kids Definition

accident

noun

ac·​ci·​dent ˈak-səd-ənt 

-sə-ˌdent

1

a

: an event occurring by chance or from unknown causes

b

: chance entry 1 sense 1

we met by accident

2

: an unintended and usually sudden and unexpected event resulting in loss or injury

an automobile accident

Medical Definition

accident

noun

ac·​ci·​dent ˈak-səd-ənt  -sə-ˌdent; ˈaks-dənt 

1

: an unfortunate event resulting from carelessness, unawareness, ignorance, or a combination of causes

2

: an unexpected bodily event of medical importance especially when injurious

a cerebrovascular accident

3

: an unexpected happening causing loss or injury which is not due to any fault or misconduct on the part of the person injured but for which legal relief may be sought

accidental

ˌak-sə-ˈdent-ᵊl 

adjective

accidentally

-ˈdent-lē, -ᵊl-ē 

adverb

also accidently

-ˈdent-lē 

Legal Definition

accident

noun

ac·​ci·​dent

: an unexpected usually sudden event that occurs without intent or volition although sometimes through carelessness, unawareness, ignorance, or a combination of causes and that produces an unfortunate result (as an injury) for which the affected party may be entitled to relief under the law or to compensation under an insurance policy see also unavoidable accident

Note: The term accident has been held to include intentional acts (such as an assault and battery) under workers' compensation laws.

accidental adjective

accidentally adverb

also accidently