Learner's definition of DANGEROUS
[more dangerous; most dangerous]
1 : involving possible injury, harm, or death : characterized by danger
— often + to
Mining is dangerous [=hazardous] work.
They complained to their boss about the dangerous [=unsafe] working conditions.
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.
2 : able or likely to cause injury, pain, harm, etc.
The storms may cause dangerous flooding.
He is wanted for assault with a dangerous weapon.
the most dangerous of drugs
a dangerous enemy
The police say that the man is armed and dangerous. [=he has a gun and he might try to shoot someone]
: a situation in which you may do or say something that will have a bad result, make people angry, etc.
As the conversation turned to politics, I knew we were heading into dangerous territory.
You know you're treading on dangerous ground, don't you?