A condition affecting a person on the basic genetic level in which one chromosome splits in three instead of two and causes heart defects, thyroid conditions, shorter extremities and slower brain development. Although, their brains are slower to develop, you won't find any of them judging so harshly that they will be sending ignorant definitions out for everyone to see. They will also never judge you for having no genetic reason to be as stupid as you so obviously represent yourself to be, as referenced by your definitions.
My niece has Down Syndrome and she is one of the joys of my life. She is not ugly in body nor in spirit. In fact, she loves unconditionally, so unlike those of us who take kindness for granted so much that we forget how to show it.