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

He was then thrust into a fatal four-way match for the Undisputed WWE Championship at Royal Rumble in 2024 against Reigns, AJ Styles and Randy Orton. — Ryan Gaydos Outkick, FOXNews.com, 5 Oct. 2026

The sting can be fatal for humans in cases of an allergic reaction, the study says. — Mark Price, Charlotte Observer, 5 Oct. 2026

Symptoms typically appear within one to two days of exposure, and patients require treatment within 48 hours of showing symptoms to prevent fatal complications. — Erika Edwards, NBC news, 5 Oct. 2026

Petrie didn’t note any evidence of fatal trauma on the remains, but the field has advanced considerably over the last century. — Jennifer Ouellette, ArsTechnica, 5 Oct. 2026