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

Slow-moving storms fueled by tropical moisture are producing dangerous rainfall rates across Central Texas, with isolated areas at risk of life-threatening flooding. —Brandi D. Addison, USA Today, 15 June 2026

Flood watches for the dangerous setup have been issued for nearly 18 million people from central Texas to central Mississippi. —Chris Dolce, CNN Money, 15 June 2026

The researchers say the technology could be used in self-driving cars, autonomous robots, and monitoring systems that operate in dangerous environments. —Neetika Walter, Interesting Engineering, 15 June 2026

The incidents have raised questions about who is responsible for regulating companies that handle dangerous materials. —Martha Bellisle, Chicago Tribune, 28 May 2026