Synonyms of dangerous

dangerous

adjective

ˈdān-jə-rəs 

1

as in hazardous

involving potential loss or injury

the soldiers were specially selected to go on a dangerous mission behind enemy lines

Synonyms & Similar Words

• hazardous
• risky
• perilous
• serious
• unsafe
• precarious
• treacherous
• menacing
• threatening
• unhealthy
• random
• fatal
• destructive
• grave
• grievous
• venturesome
• detrimental
• harmful
• parlous
• unpleasant
• uncertain
• bad
• lethal
• deadly
• jeopardizing
• sickening
• adverse
• murderous
• nasty
• insecure
• fell
• ugly
• haphazard
• dicey
• killer
• injurious
• chance
• distressing
• pernicious
• malignant
• evil
• wicked
• deleterious
• noxious
• hurtful
• ultrahazardous
• dire
• baneful
• inimical
• fateful
• ill
• mortal
• baleful
• pestilent
• deathly

Antonyms & Near Antonyms

• safe
• harmless
• innocuous
• innocent
• beneficial
• nonthreatening
• nonhazardous
• good
• advantageous
• unthreatening
• ultrasafe

2

as in harmful

causing or capable of causing harm

the common knowledge that smoking is dangerous to one's health hasn't stopped some people

Synonyms & Similar Words

• harmful
• detrimental
• damaging
• adverse
• hazardous
• bad
• poisonous
• injurious
• infectious
• pernicious
• evil
• deleterious
• noxious
• prejudicial
• hurtful
• mischievous
• baneful
• wicked
• deadly
• ill
• unsafe
• destructive
• hostile
• nocuous
• baleful
• risky
• lethal
• sinister
• venomous
• perilous
• infective
• threatening
• ominous
• unfriendly
• insidious
• inimical
• menacing
• fatal
• contagious
• unhealthy
• unhealthful
• pestilential
• malignant
• unwholesome
• unsound
• ruinous
• pestiferous
• killer
• pestilent
• nasty
• parlous
• jeopardizing
• imperiling
• noisome

Antonyms & Near Antonyms

• safe
• harmless
• benign
• innocuous
• beneficial
• useful
• innocent
• advantageous
• good
• inoffensive
• favorable
• healthy
• helpful
• propitious
• healthful
• wholesome
• anodyne
• remedial
• salubrious
• salutary
• curative
• hurtless
• sound
• secure
• palliative
• nontoxic
• nonpoisonous
• nondestructive
• benignant
• noninfectious
• noncorrosive
• nonfatal
• nonlethal
• nonpolluting
• nonvenomous

Synonym Chooser

How is the word dangerous distinct from other similar adjectives?

Some common synonyms of dangerous are hazardous, perilous, precarious, and risky. While all these words mean "bringing or involving the chance of loss or injury," dangerous applies to something that may cause harm or loss unless dealt with carefully.

soldiers on a dangerous mission

When could hazardous be used to replace dangerous?

The meanings of hazardous and dangerous largely overlap; however, hazardous implies great and continuous risk of harm or failure.

claims that smoking is hazardous to your health

When can perilous be used instead of dangerous?

The synonyms perilous and dangerous are sometimes interchangeable, but perilous strongly implies the immediacy of danger.

perilous mountain roads

When might precarious be a better fit than dangerous?

In some situations, the words precarious and dangerous are roughly equivalent. However, precarious suggests both insecurity and uncertainty.

earned a precarious living by gambling

When is it sensible to use risky instead of dangerous?

The words risky and dangerous can be used in similar contexts, but risky often applies to a known and accepted danger.

shied away from risky investments

Example Sentences

Recent Examples of dangerous

Mixing bleach with other substances (such as rubbing alcohol, vinegar and ammonia) can lead to toxic chemical reactions that can be dangerous to your health and floors. — Stephanie Osmanski, Better Homes & Gardens, 26 Sep. 2026

The broader concept envisions robots entering dangerous areas after sensors identify a threat, reducing the need to expose soldiers to direct danger. — Bojan Stojkovski, Interesting Engineering, 26 Sep. 2026

Earlier this month, Santa Monica’s inaugural Ocean Way Festival was scrapped amid dangerous high surf and flooding caused by Hurricane Marie across Southern California. — Charisma Madarang, Rolling Stone, 25 Sep. 2026

This creates a dangerous gap between accounting profitability and financial reality. — Prasanna Kumar, Forbes.com, 25 Sep. 2026