Ill is when you're freaking sick (haha, look, the title of this article looks like three).
People who go to school may feel ill.
When people feel sick and they don't want to go somewhere and then the parents get really mad at them and then they bomb their Social Studies test, making a 69.49 and not being able to make it up because you are sick for the next week. You come home and everyone greets you happily and then you tell them the bad news and then they spank you 17 and 2/3 times and then they lock you in your room and then they make you go to bed early and then they make you watch an episode of the Simpsons. Edit