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

Officials warn this can lead to more aggressive behavior and increase the likelihood of dangerous encounters, and, in some cases, lead to bears being euthanized. —Kelly McGreal, FOXNews.com, 20 Apr. 2026

Even exercising aboard the ISS could be dangerous if someone’s grip were to slip. —Chelsea Gohd, Space.com, 20 Apr. 2026

After rising inexorably through 2022, when these dangerous drugs killed 3,160 Illinois residents in a single year, the trend finally has reversed. —The Editorial Board, Chicago Tribune, 20 Apr. 2026

Questions included whether 5G technology or antiperspirants cause cancer, which vaccines are dangerous and whether anabolic steroids are safe. —Kaan Ozcan, NBC news, 20 Apr. 2026