Meanings of wily savages in английском

The wily savages had chosen their ground well for this purpose.

What could two boys do against half a dozen wily savages?

The wily savages, unseen and unheard, crept near, and piercing him with their arrows he fell dead.

These wily savages had, out of all question, taken their opportunity to remove and secrete these simple, but almost indispensable, means of motion.