I have a severely autistic brother who is in a group home, and I use the word "retard" all the time. Why? Because I’m not oversensitive and I am not actually calling my brother it. an asshole.
The word "retard" derives itself from the term "mental retardation", which is found in the DSM, the DSM-II, the DSM-III, and the DSM-IV. Only recently (i.e. around the time of the release of the DSM-5) has the APA decided to begin using the term "intellectual disability" instead, because, for some strange reason, a lot of overly-sensitive people disapprove of the perfectly fitting word "retard".
