The difference between Dangerous and Harmless

When used as adjectives, dangerous means full of danger, whereas harmless means incapable of causing harm or danger.

check bellow for the other definitions of Dangerous and Harmless

Dangerous as an adjective:

Full of danger.

Examples:

"Railway crossings without gates are highly dangerous."
Dangerous as an adjective:

Causing danger; ready to do harm or injury.
Dangerous as an adjective (colloquial, dated):

In a condition of danger, as from illness; threatened with death.
Dangerous as an adjective (obsolete):

Hard to suit; difficult to please.
Dangerous as an adjective (obsolete):

Reserved; not affable.