Does anyone use this word like this?

It's basically like this, retard in my mind means "a person so very stupid that they will never become intelligent".You can look into these people's eye and tell they are dull human beings that have no under lying important thoughts ever.They are just unreasonable and don't know anything about manners.I say "retarded" as it was used in the 50s or in the form of my definition.I don't think I shouldnt have to use another definition.The alternatives dont make sense.Retarded used to be a word for all mental disorders in general because it was believe they would never be fully mature in freud's view and it is sometimes used as a blunt form of the word(the people that do so are retarded and can't let language evolve in my opinion).