Synonyms of perilous

perilous

adjective

ˈper-ə-ləs 

as in dangerous

involving potential loss or injury

a perilous journey through hostile territory

Synonyms & Similar Words

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

Antonyms & Near Antonyms

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

Synonym Chooser

How is the word perilous distinct from other similar adjectives?

Some common synonyms of perilous are dangerous, hazardous, precarious, and risky. While all these words mean "bringing or involving the chance of loss or injury," perilous strongly implies the immediacy of danger.

perilous mountain roads

When might dangerous be a better fit than perilous?

The words dangerous and perilous are synonyms, but do differ in nuance. Specifically, dangerous applies to something that may cause harm or loss unless dealt with carefully.

soldiers on a dangerous mission

When is it sensible to use hazardous instead of perilous?

The synonyms hazardous and perilous are sometimes interchangeable, but hazardous implies great and continuous risk of harm or failure.

claims that smoking is hazardous to your health

When can precarious be used instead of perilous?

While in some cases nearly identical to perilous, precarious suggests both insecurity and uncertainty.

earned a precarious living by gambling

When would risky be a good substitute for perilous?

In some situations, the words risky and perilous are roughly equivalent. However, risky often applies to a known and accepted danger.

shied away from risky investments

Example Sentences

Recent Examples of perilous

Conversely, households marked by conflict or instability can leave independence feeling perilous, even unsafe. —Mark Travers, Forbes.com, 13 Sep. 2025

Starting the season 0-2 has proven perilous for NFL teams with postseason aspirations. —Kansas City Star, 12 Sep. 2025

Every episode of Destruction Decoded delves deep into a type of historical disaster, such as train crashes, bridge collapses, or perilous expeditions. —PC Magazine, 12 Sep. 2025

Each breakthrough spoke to what could be imagined, while also exposing how perilous progress could be. —Okla Jones, Essence, 10 Sep. 2025