a chromosomal (
big word for
smart people) disorder which effects someone for they're whole life. They have swollen looking eyes and difficulty with learning. they can also be insanely strong, i know a little girl with down syndrome, she is 9 and she can push an 80kg man to the ground. no problems. good thing is, they are very very nice people and generally more fun and outgoing than most of the nerds who
will read this XD.
in short, if you call someone who did something stupid 'a downy' or 'down syndrome' you obviously don't know anyone who has it or have ever properly met someone who has it.