fatal

adjective

fa·​tal ˈfā-tᵊl 

1

a

: causing death

a fatal crash

a fatal disease

a fatal wound

b

: bringing ruin

a fatal attraction to gambling

c

: causing failure

a fatal design flaw

Lack of sufficient support was fatal to his campaign.

2

a

: determining one's fate

… the fatal flaw in this dazzling woman: a total lack of taste.

—Marya Mannes

b

: of or relating to fate

… this science sets a fatal necessity on things …

—Henry Osborn Taylor

c

: resembling fate in proceeding according to a fixed sequence

3

: fateful

a fatal hour

4

obsolete : fated

Synonyms of fatal

• disastrous
• catastrophic
• unfortunate

Choose the Right Synonym for fatal

deadly, mortal, fatal, lethal mean causing or capable of causing death.

deadly applies to an established or very likely cause of death.

a deadly disease

mortal implies that death has occurred or is inevitable.

a mortal wound

fatal stresses the inevitability of what has in fact resulted in death or destruction.

fatal consequences

lethal applies to something that is bound to cause death or exists for the destruction of life.

lethal gas

Examples of fatal in a Sentence

a disease that is often fatal

a chemical that can be fatal to birds

She made a fatal mistake.

Recent Examples on the Web

The individual who inflicted the fatal injury drove the spear downward through the victim’s left chest cavity from the front, piercing major arteries and the lungs before creating the hole in the left scapula. — Andrew Paul, Popular Science, 15 Oct. 2026

The series is notorious for its shocking plot twists (many of which bring dramatic, fatal ends to important characters). — Brendan Le, PEOPLE, 15 Oct. 2026

Clark Atlanta University is mourning student Morgan Gamble after a driver struck her vehicle in a fatal crash Tuesday night in Atlanta. — Christopher Harris, CBS News, 15 Oct. 2026

Thursday morning, the Independence Police Department released the name of the victim in a fatal Sunday collision with a patrol vehicle, along with the identity of the officer behind the wheel. — Eleanor Nash, Kansas City Star, 15 Oct. 2026

Word History

Etymology

Middle English, from Latin fatalis, from fatum fate

First Known Use

14th century, in the meaning defined at sense 4

Phrases Containing fatal

• dealt a fatal blow

Rhymes for fatal

• datal
• antenatal
• hiatal
• neonatal
• perinatal
• nonfatal
• postnatal
• prenatal

Kids Definition

fatal

adjective

fa·​tal ˈfāt-ᵊl 

1

: deciding one's fate : fateful

on that fatal day

2

: causing death or ruin

a fatal accident

fatally

-ᵊl-ē

adverb

Medical Definition

fatal

adjective

fa·​tal ˈfāt-ᵊl 

: causing death

a fatal diabetic coma

—Havelock Ellis

fatally

ˈfāt-ᵊl-ē 

adverb

Legal Definition

fatal

adjective

fa·​tal

1

: causing failure of a legal claim or cause of action

a fatal defect in the proceedings

—W. R. LaFave and J. H. Israel

2

: making something (as a contract) invalid or unenforceable

there is a fatal indefiniteness with the result that the agreement is void

—J. D. Calamari and J. M. Perillo

fatally adverb