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

Nothing could be more fatal to a work of fiction. —Judith Shulevitz, The Atlantic, 17 Feb. 2026

Ballard said his office pursues murder charges in fatal overdose cases against anyone who provides drugs to a person who overdoses. —Ari Fife, The Frontier, 17 Feb. 2026

This case is one of several nationwide where prosecutors are attempting to hold parents criminally responsible for fatal shootings carried out by their children. —Jeff Martin, Los Angeles Times, 17 Feb. 2026

Mexican officials also probed whether the fatal shooting was related to her denouncing drug dealers in her neighborhood. —Alexandra Mendoza, San Diego Union-Tribune, 16 Feb. 2026