dangerous

adjective

dan·​ger·​ous ˈdān-jə-rəs 

ˈdān-jərs, 

-zhrəs

1

: involving possible injury, pain, harm, or loss : characterized by danger

a dangerous job

2

: able or likely to inflict injury or harm

a dangerous man

dangerously adverb

dangerousness noun

Synonyms of dangerous

• hazardous
• risky
• perilous
• serious
• unsafe

Choose the Right Synonym for dangerous

dangerous, hazardous, precarious, perilous, risky 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

hazardous implies great and continuous risk of harm or failure.

claims that smoking is hazardous to your health

precarious suggests both insecurity and uncertainty.

earned a precarious living by gambling

perilous strongly implies the immediacy of danger.

perilous mountain roads

risky often applies to a known and accepted danger.

shied away from risky investments

Examples of dangerous in a Sentence

She got into a car accident while driving through a dangerous intersection.

He often drives at dangerous speeds.

The city can be a dangerous place to live.

The storms may cause dangerous flooding.

He is wanted for assault with a dangerous weapon.

the most dangerous of drugs

Recent Examples on the Web

Interestingly, this new Wi-Fi chip could finally enable the wireless control needed to make these dangerous cleanups faster and safer. —Mrigakshi Dixit, Interesting Engineering, 24 Mar. 2026

The chief medical officer for Huntington Beach Fire said the Southern Pacific rattlesnake found locally can produce a highly dangerous neurotoxic venom. —Michele Gile, CBS News, 24 Mar. 2026

The scorching heat wave, which began last week and brought dangerous temperatures to parts of California, Arizona, and other Southwestern states, is expected to expand east into the central United States in the coming days, according to the National Weather Service. —Thao Nguyen, USA Today, 23 Mar. 2026

But as the region teeters on the brink of a new and dangerous escalation, yet more negative consequences – like the evils that escaped Pandora’s box – could soon be unleashed. —Matthew Chance, CNN Money, 23 Mar. 2026

Word History

Etymology

see danger entry 1

First Known Use

15th century, in the meaning defined at sense 1

Phrases Containing dangerous

• armed and dangerous
• dangerous ground/territory
• dangerous waters
• on dangerous ground

Kids Definition

dangerous

adjective

dan·​ger·​ous ˈdānj-(ə-)rəs 

1

: exposing to or involving danger

a dangerous mission

2

: able or likely to cause injury

dangerous weapons

dangerously adverb

dangerousness noun

Legal Definition

dangerous

adjective

dan·​ger·​ous

1

: creating a risk of bodily injury

a dangerous condition of a public building

2

: able or likely to inflict especially serious bodily injury

a dangerous criminal with no regard for human life

a dangerous animal

also : deadly

3

: likely to engage in repeated criminal activity

a dangerous offender

Note: The activity that an offender is likely to engage in need not involve violence in order for the offender to be deemed dangerous.