Synonyms of fatal

fatal

adjective

ˈfā-tᵊl 

1

as in disastrous

bringing about ruin or misfortune

I made the fatal mistake of sharing my secret with the office's biggest blabbermouth

Synonyms & Similar Words

• disastrous
• catastrophic
• unfortunate
• destructive
• fateful
• ruinous
• calamitous
• damning
• adverse
• damaging
• apocalyptic
• harmful
• cataclysmal
• detrimental
• injurious
• pernicious
• deleterious
• luckless
• hapless
• baneful
• evil
• prejudicial
• ill-fated
• ill-starred
• hurtful
• noxious
• ill
• baleful

Antonyms & Near Antonyms

• fortuitous
• lucky
• fortunate
• happy
• providential
• fair
• promising
• fluky
• golden
• optimistic
• propitious
• bright
• encouraging
• hopeful
• rosy
• auspicious
• heartening
• upbeat
• rose-colored

2

as in lethal

likely to cause or capable of causing death

that snake's venom is fatal unless the victim is given the antidote almost immediately

Synonyms & Similar Words

• lethal
• deadly
• poisonous
• infectious
• infective
• killer
• harmful
• terminal
• dangerous
• toxic
• deathly
• mortal
• murderous
• baleful
• injurious
• fell
• destructive
• hazardous
• pernicious
• vital
• deleterious
• pestilent
• serious
• baneful
• virulent
• risky
• perilous
• sublethal
• noxious
• pestilential
• threatening
• ugly
• bloody
• truculent
• grievous
• menacing
• sanguinary
• unhealthy
• grave
• parlous
• unsound
• jeopardizing
• sanguine
• internecine

Antonyms & Near Antonyms

• nonfatal
• healthy
• beneficial
• healthful
• nonlethal
• wholesome
• salutary
• corrective
• salubrious
• remedial
• restorative
• curative
• useful
• advantageous
• tonic
• safe
• nontoxic
• alleviative
• nonpoisonous

Synonym Chooser

How does the adjective fatal differ from other similar words?

Some common synonyms of fatal are deadly, lethal, and mortal. While all these words mean "causing or capable of causing death," fatal stresses the inevitability of what has in fact resulted in death or destruction.

fatal consequences

When is it sensible to use deadly instead of fatal?

While the synonyms deadly and fatal are close in meaning, deadly applies to an established or very likely cause of death.

a deadly disease

When would lethal be a good substitute for fatal?

The meanings of lethal and fatal largely overlap; however, lethal applies to something that is bound to cause death or exists for the destruction of life.

lethal gas

When might mortal be a better fit than fatal?

The synonyms mortal and fatal are sometimes interchangeable, but mortal implies that death has occurred or is inevitable.

a mortal wound

Example Sentences

Recent Examples of fatal

Gajdusek had come to the idea of injecting animals after a veterinary pathologist noticed that the brains of kuru patients resembled those of sheep with scrapie, a fatal neurological disease transmitted through exposure to infected tissues. — Rachel Aviv, New Yorker, 17 Aug. 2026

State police have arrested a man in connection with a fatal head-on crash in Middlefield last August after investigators found that his blood alcohol content was allegedly more than twice the legal limit. — Justin Muszynski, Hartford Courant, 15 Aug. 2026

No direct evidence has been put forth linking Samson’s fatal flight to an electrical jolt. — Thomas Tracy, New York Daily News, 15 Aug. 2026

Police also said that officers in the area reported seeing the motorcycle pass them at a high rate of speed on the freeway about 10 minutes before the fatal crash. — Harriet Ramos, Fort Worth Star-Telegram, 15 Aug. 2026