A loaded question is a type of question that has an answer built into it. This can make it difficult to respond to because it assumes that a certain answer is true. For example:
"Why aren't you making more money? Do you not care about your future?"
In this question, the person asking it is assuming that their listener ought to be making more money, and that they should care about their future. It's a difficult question to answer, since it makes it seem like those things ought to be true.