Not Good
Hopeless, Cannot, Not Allowed
noun, な adjective
If something is burdensome to the eye (when you look at it), you know that that thing is not good or hopeless. Just look at that burdensome thing with your eye. This can also mean not allowed. Parents say this to their kids all the time.
The readings are the readings you learned with the kanji.
男の子と旅行に行くのは、絶対に駄目ですからね！
You absolutely cannot go on a trip with a boy!