fatal

fatal — adjective

1. leading directly to someone's death — used for illnesses, injuries, and accident

1.adjectiveB2
Definition

leading directly to someone's death — used for illnesses, injuries, and accidents that end a person's life.

Example

Tariq's uncle died from a fatal heart attack while he was working in the garden.

collocation: fatal heart attack

The doctor told Élise that the injury to her spine was not fatal.

predicative use: be fatal

Common collocations
  • fatal heart attack
  • fatal accident
  • fatal injury
  • fatal illness
  • fatal disease
  • fatal wound
  • fatal blow
  • fatal dose
Synonyms
  • deadly

    broader — can mean 'able to cause death' rather than 'actually causing death'; 'a deadly poison' may only be dangerous in large doses

  • lethal

    more technical and clinical; often used for weapons, chemicals, or doses ('a lethal injection')

  • mortal

    more formal and literary; used for wounds, blows, or enemies ('a mortal wound')

Antonyms
  • non-fatal

    the direct opposite in medical/report contexts ('non-fatal injuries')

  • harmless

    stronger contrast — not causing any harm at all

Grammar Patterns

fatal + noun

be fatal

prove fatal

be fatal to + noun

Usage Note

Used mainly in medical and accident contexts. The pattern 'prove fatal' is frequent in formal writing and news reports, while 'be fatal' is more neutral and common in everyday speech.

Common Mistakes

The doctor said the injury was fatal but he recovered.
The doctor said the injury was potentially fatal, but he recovered.
'fatal' means death has actually occurred or is certain; use 'potentially fatal' for possibility.

2. so serious that it causes complete failure or total ruin — used of decisions, mi

2.adjectiveB2
Definition

so serious that it causes complete failure or total ruin — used of decisions, mistakes, or design flaws that destroy any chance of success.

Example

João made a fatal mistake when he sent the email to the wrong client.

collocation: fatal mistake

The team's lack of preparation proved fatal to their chances of winning.

pattern: prove fatal to + noun

Common collocations
  • fatal mistake
  • fatal error
  • fatal flaw
  • fatal consequence
  • fatal blow to
  • fatal to + noun
Synonyms
  • disastrous

    similar intensity but slightly broader — can describe events that cause widespread suffering, not just failure ('a disastrous flood')

  • devastating

    emphasises the emotional or psychological impact of the ruin ('devastating news')

  • catastrophic

    suggests a very large scale of disaster ('catastrophic economic collapse')

Antonyms
  • minor

    describes problems with small, manageable consequences

  • harmless

    causing no damage at all

  • beneficial

    producing a good result, the opposite of destructive

Grammar Patterns

fatal + noun

be fatal to + noun

prove fatal

Usage Note

Unlike sense 1 ('CAUSING DEATH'), this sense does NOT involve physical death. The object of ruin is typically abstract: plans, careers, projects, or reputations. The preposition 'to' follows 'fatal' when specifying what is ruined: 'The delay was fatal to our deal.'

Common Mistakes

I made a fatal error in my homework and lost two points.
I made a careless error in my homework and lost two points.
'fatal' means completely destructive, not a minor mistake that only loses a few points.

Word family

  • fatally
    adverbB2
  • fatality
    nounB2
  • fatalism
    nounC1
  • fatalist
    nounC1
  • fatalistic
    adjectiveC1

Synonym discussion

Sense: adjective/1

All four words describe something that can cause death, but they differ in tone and typical use. 'Fatal' is the most neutral and factual — it focuses on the outcome (death actually results), making it the best choice for medical reports and news: 'The disease proved fatal in 30% of cases.' 'Deadly' is broader and more dramatic; it means 'capable of causing death' but does not guarantee it happens — 'a deadly poison' may still have an antidote. 'Lethal' is more technical and is the standard term for doses, injections, and chemical agents in clinical and legal language: 'The lethal dose of the drug is 500 milligrams.' 'Mortal' is the most formal and literary of the four, found in expressions like 'a mortal wound' or 'mortal combat' — it carries an old-fashioned, epic flavour and is rare in everyday speech.

fatal ↗deadly ↗lethal ↗mortal

Common collocations

Nouns

Adverbs

Phrases

  • prove fatal
  • be fatal
  • something proves fatal

Prepositions

Etymology

LatinFrenchEnglish

From the Latin word 'fatalis', meaning 'ordained by fate' or 'deadly'. 'Fatalis' itself comes from 'fatum' (fate, destiny), the same root that gives us the word 'fate'. In classical Latin, 'fatalis' carried both the sense of 'decreed by destiny' and 'bringing death' — the connection being that death was seen as something destined. The 'causing death' meaning became dominant in English by the 1600s, while the broader 'causing ruin' sense developed later.