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

Extreme heat becomes more dangerous when people are physically active, the CDC says. — Janet Loehrke, USA Today, 25 June 2026

Firefighters have been battling the flames for seven days now, and smoke has made air dangerous to breathe in neighborhoods across the Los Angeles region. — Noah Goldberg, Los Angeles Times, 24 June 2026

Instead, the area should be cleared of sharp or dangerous objects; they should be turned gently on their side, and their airway should be kept clear. — Shafiq Najib, ABC News, 24 June 2026

Police described the shootings as an isolated incident and warned the public that Sanchez-Munoz was considered armed and dangerous during a press conference on Wednesday, June 17. — Kacen Bayless, Kansas City Star, 24 June 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.