“Retarded” has an older literal meaning and a modern, very offensive slang meaning, and it is now strongly discouraged in everyday use.

Main meanings

  • In older medical/technical use, “retarded” meant having slower mental development or intellectual functioning than typical , as in “mentally/emotionally retarded.”
  • In a more general, non‑medical sense, it can mean slowed or delayed , as in “the heavy backpack retarded (slowed) his progress.”

Why it’s offensive now

  • Dictionaries now label the word as “old-fashioned,” “dated,” and “offensive,” especially when used about people.
  • It has often been used as an insult meaning “stupid” or “very foolish,” which is considered disrespectful to people with intellectual disabilities.
  • Modern guidance recommends saying “person with an intellectual disability” or “learning disability” instead of “retarded.”

How people talk about it online

  • Some forum users argue that the original meaning is just “delayed” or “behind,” but even they often admit that using it directly about a person is rude.
  • Others point out that phrases like “What are you, retarded?” clearly function as insults and are criticized as insensitive.

So, should you use it?

  • Using it to mean “stupid” is widely seen as hurtful and disrespectful today.
  • In professional, school, and most social settings, it’s better to avoid the word and use respectful, up‑to‑date terms like “intellectual disability,” “learning disability,” or “developmental delay.”

TL;DR: “Retarded” originally meant “mentally delayed” or “slowed,” but as a label for people it is now considered outdated and offensive, especially when used as an insult, so it’s best not to use it.

Information gathered from public forums or data available on the internet and portrayed here.