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

The announcement, first reported by The New York Times, comes after the National Transportation Safety Board cited the lack of such transponders as a possible contributing factor in last month’s fatal crash between a landing jet and a fire-rescue truck at LaGuardia. —Evan Simko-Bednarski, New York Daily News, 28 Apr. 2026

Over the course of the past year, Texas state lawmakers have been investigating the fatal July 4, 2025, floods that claimed over 130 lives, including those of 27 young girls at a Central Texas summer camp. —Mateo Rosiles, USA Today, 27 Apr. 2026

Saturday’s bombing was the most fatal in a string of attacks in Cauca in recent days, which is one of the regions most affected by Colombia’s internal armed conflict. —Alfie Pannell, Miami Herald, 27 Apr. 2026

Researchers tracked more than 2,200 direct threats to CEOs across different channels in the five weeks following the fatal shooting of UnitedHealthCare CEO Brian Thompson in late 2024, more than the entire year that preceded it. —Diane Brady, Fortune, 27 Apr. 2026