fail

1 of 2

verb

ˈfāl 

failed; failing; fails

intransitive verb

1

a

: to lose strength : weaken

her health was failing

b

: to fade or die away

until our family line fails

c

: to stop functioning normally

the patient's heart failed

2

a

: to fall short

failed in his duty

b

: to be or become absent or inadequate

the water supply failed

c

: to be unsuccessful

the marriage failed

specifically : to be unsuccessful in achieving a passing grade

took the exam and failed

d

: to become bankrupt or insolvent

banks were failing

transitive verb

1

a

: to disappoint the expectations or trust of

her friends failed her

b

: to miss performing an expected service or function for

his wit failed him

2

: to be deficient in : lack

never failed an invincible courage

—Douglas MacArthur

3

: to leave undone : neglect

fail to lock the door

4

a

: to be unsuccessful in passing

failed chemistry

b

: to grade (someone, such as a student) as not passing

The teacher failed only his two worst students.

failingly

ˈfā-liŋ-lē 

adverb

fail

2 of 2

noun

plural fails

1

: failure

—usually used in the phrase without fail

Every day, without fail, he has toast and coffee for breakfast.

see also epic fail

2

: a failure (as by a security dealer) to deliver or receive securities within a prescribed period after purchase or sale

Synonyms

Verb

• die
• crash

Examples of fail in a Sentence

Verb

He failed in his first attempt but succeeded in his second attempt.

His first company failed, but his second company succeeded.

He felt that he had failed her when she needed him most.

The government has failed the voters.

Recent Examples on the Web

Verb

Renard was not the only one who failed to make the cut. —Charlotte Harpur, New York Times, 5 July 2025

In the corporate world, companies that fail to keep up with advances in hardware, software or technology platforms could face a different type of crisis: being at a competitive disadvantage in a challenging and demanding marketplace. —Edward Segal, Forbes.com, 5 July 2025

Noun

The labs report their results in varied ways, including numeric scores, pass/fail, and named certification tiers. —PC Magazine, 4 June 2025

There is a complete fail in the attempt to nurture and develop emotion on the stage, which some might excuse as just being intentionally reflective of Diamond’s own reluctance to come clean with himself about his troubles and concerns in therapy. —Jim Harrington, Mercury News, 6 June 2025

Word History

Etymology

Verb and Noun

Middle English failen, from Anglo-French faillir, from Vulgar Latin *fallire, alteration of Latin fallere to deceive, disappoint

First Known Use

Verb

13th century, in the meaning defined at intransitive sense 1a

Noun

13th century, in the meaning defined at sense 1

Phrases Containing fail

• epic fail
• fail-safe
• fail to see/understand
• pass-fail
• without fail
• words fail someone

Rhymes for fail

• ail
• ale
• bail
• baile
• dail
• flail
• frail
• gael
• gail
• grail
• hail
• jail

Kids Definition

fail

1 of 2 verb

ˈfā(ə)l 

1

a

: to lose strength : weaken

failing eyesight

b

: to stop functioning

the engine failed

2

a

: to fall short

failed in their duty

b

: to become absent or lacking

the power failed

c

: to be unsuccessful (as in passing an examination)

d

: to grade as not passing

fail a student

e

: to become bankrupt

3

: disappoint, desert

fail a friend in need

4

: to leave undone : neglect

fail to answer the telephone

fail

2 of 2 noun

: failure sense 1

—usually used in the phrase without fail

Medical Definition

fail

intransitive verb

ˈfā(ə)l 

1

: to weaken or lose strength

her health was failing

2

: to stop functioning normally

the patient's heart failed

Legal Definition

fail

intransitive verb

1

: to be or become inadequate or unsuccessful especially in fulfilling certain formal requirements

even if one or more terms are left open, a contract for sale does not fail for indefiniteness

—Uniform Commercial Code

2

: to become bankrupt or insolvent

transitive verb

: to leave undone or neglect to do

fail to appear in court

fail to read a contract