The word retard dates as far back as 1426. It stems from the Latin verb retardare, meaning to hinder or make slow. The English adopted the word and used it as similar meaning, slow and delayed. The word "to decelerate" would become a more common term than "to retard".
History, Modern Use, and Legislation
In modern use, retard is a pejorative term. Because it is now considered offensive, the word is commonly referred to by the euphemisms "r-word" and "r-slur".
It was previously used as a medical term. The verb "to retard" means to delay or hold back, and so "retard" became known as a medical term in the late 19th and early 20th centuries to describe children with intellectual disabilities, or retarded mental development. Up until around the 1960s, the terms "moron", "idiot", "cretin" and "imbecile" were all genuine, non-offensive terms to refer to people with mental intellectual disabilities and low intelligence. These words were discontinued in that form when concerns arose that they had developed negative meanings, with "retard" and "retarded" replacing them. After that, the terms "handicapped" (United States) and "disabled" (United Kingdom) replaced "retard" and "retarded". Disabled is now considered a more polite term than handicapped in the United States as well.
Much like today's widely socially acceptable terms idiot and moron, which are also defined as some sort of mental disability, when the term retard is being used in its pejorative form, it is usually not being directed at people with mental disabilities. Instead, people use the term when teasing their friends or as a general insult.
As of 2010, despite not typically being used in official context, "mental retardation" was still written in many of the United States' laws and documents, considered by many to be outdated. U.S. President Barack Obama replaced the term with "intellectual disability" with the approval of Rosa's Law—which would require these laws and documents to phase out the terms with the "intellectual disability" term.
On October 5, 2010, Obama signed S. 2781 into law. Known as Rosa's Law, the bill changed references in federal law; the term mental retardation was replaced by mental disability. Additionally, the phrase "mentally retarded individual" was replaced with "an individual with an intellectual disability". Rosa's Law was named after Rosa Marcellino, a nine-year-old girl with Down syndrome. She worked with her parents to have the words "mentally retarded" officially removed from health and education code in Maryland, her home state. With this new law, "mental retardation" and "mentally retarded" no longer exist in federal health or education and labor policy. The rights of individuals with disabilities would remain the same. The goal of this word removal was to remove language that may be considered hurtful from communities.