1. - ignorant
Ignorant is a word that is used to refer to someone who lacks factual knowledge or information about a certain person, thing or idea but he actually believes he has the knowledge about that thing, person or idea. The funny thing about this word is that most people who use it actually assume they have factual knowledge about something and so they call those who disagree with them ignorant. However, they are in fact the ones who are ignorant since their knowledge is not factual. They are more ignorant because they think they know while they really do not know. For these kinds of ignorant people, it is advised that you leave them as they are since trying to inform them any better can lead to you getting a black eye or worse still, a broken nose.
2. - ignorant
Ignorant is also used to refer to people who absolutely have no clue about something or someone. These kinds of ignorant people do or do not try to hide their ignorance of things. They either care or do not care about their state of not knowing. Some of these people often use this same word as their defense when confronted for their ignorance on things. They will claim that you do not understand them and that you are ignorant yourself for thinking that they are ignorant. It is really infuriating arguing with an ignorant person.