What is synonym of dangerous?

Here are some synonyms for "dangerous," depending on the context:

General:

* Hazardous

* Risky

* Perilous

* Treacherous

* Unsafe

* Threatening

* Harmful

* Precarious

* Unstable

* Insecure

More intense:

* Deadly

* Lethal

* Fatal

* Destructive

* Catastrophic

More specific:

* Explosive (for something that could explode)

* Toxic (for something that is poisonous)

* Infectious (for something that can spread disease)

* Corrosive (for something that can eat away at materials)

* Flammable (for something that can easily catch fire)

The best synonym will depend on the specific situation you're describing.