No.528035
Words are man-made tools to describe the world as we perceive it, and to patch over differences in said perception from person to person. They mean whatever people agree they mean, and that's it. Any attempts to find the "true" meaning of a word are at bottom idealism, and not worth seriously considering.
No.528062
Disability is mostly dependent on context, but basically amounts to when somebody can't do what most people can. Whether this requires special accommodations or not is another question that again depends on context. Having some kind of inconvenient medical condition doesn't make you disabled unless the inconvenience interferes with your ability to function (without intervention or accommodation - it's still a disability even if you manage it effectively).