It isn't really necessary to define words on HN. I think most of us have a good idea of what common English words mean. It appears as though you genuinely, by

It isn't really necessary to define words on HN. I think most of us have a good idea of what common English words mean. It appears as though you genuinely, by your own admission, have no knowledge of the r-word's history of use in the latter half of the 20th century. My uncle was born in the late 1940s and has intellectual disabilities that were severely exacerbated by years spent in "mental health" facilities. Before that fate befell him, my grandmother founded one of the first schools for children with intellectual disabilities in her state. It was known then as the County School for Retarded Children. This was the appropriate term back then. Doctors, researchers, teachers, and legislators all used the r-word to describe people with intellectual disabilities. It took decades for that to fade from use, yet the stigma remains. This is how the term came to be conflated with people who are "considered dumb" as you say. That only makes it worse. People with intellectual disabilities are certainly not dumb. Now, you claimed that the r-word has "not ever meant mentally disabled." That's simply not true.