Stands for Attention Deficit Disorder.
A lot of people say they have it because they "sometimes have trouble paying attention in class" which is bullshit. That just means you have a boring teacher.
If you REALLY have ADD, then you can't pay attention to ANYTHING. If you try to read, do homework, watch TV, take a test, or listen to somebody, your focus will slide in and out CONSTANTLY. There is also ADHD
in which you are also hyperactive.
Most kids will take medicine like Ritalin or Focalin to help them concentrate.
Dumbass: LOLZ LIEK I TOTALLY HAVE A.D.D. CUZ I CANT STUDY FOR EXAMZ LIEK LOL
Kid with A.D.D.: You dumbass you don't actually have A.D.D.