"Able" means "having the ability to do something". Making it a verb with "en-" makes it mean "giving someone/thing else the ability to do something" - as you can see, the prefix just takes the base word and flips it around.
Take a look at "enact". The base word, "act" as a noun means "a deed" or "thing done", but adding the prefix makes a verb, flipping it around - "creating/making a thing done" (more specifically a law or bill)
Finally, "endanger". It follows the pattern - the base means "something that could cause harm", making it a verb flips it to "to put something into a situation that could cause it/them harm".
These aren't necessarily the dictionary definitions but that's the basics of what it's trying to get at
