(If you landed here after an image search,
this post is better for you.)
It's time for a little etymology lesson. There seems to be great confusion about the proper usage of the word retard.
Even Chief of Staff Rahm Emanuel is a bit discombobulated. After all, he was only trying to vent his anger and frustration at an idea presented by a group of liberal Democrats at a weekly strategy session last August, when you know, it just popped out, “Fucking retarded.”
Once his slur came to light and was publicized as a big faux-pas, Emanuel apologized. He meant no harm to the mentally disabled. He wasn’t referring to
them. He meant “retarded” in a different context... And guess what? Many bloggers are defending his use of the insult.
They say... What is with all this politically correct stuff anyway? Why are you so sensitive? Nobody calls mentally retarded people retarded... It just doesn’t mean
that anymore. Everybody knows that the modern definition of it is: stupid, nonsensical, ineffective, useless, uncooperative. Golly, its the perfect catch-all for most anything that is annoying.
The word has Latin roots and by the 1400s it meant, “to make slower in movement or time,” and forms of the word came to mean to make something or someone late... think “tardy” or the French, “Je suis en retard” which translates into “I am late” (as in for a very important date.) The English version of the word is still used in this innocuous form today... a fire retardant mattress, a chemical that retards weed growth.
So how did the word travel from fire retardant pajamas to a playground insult? What is the bridge between “late or hindered” and “stupid or aggravating”?
Hmm, let me think, let me think... what is the reference of our shared understanding of the slur?
Is it...

No, no, that's not it.
Is it...

No, though that may be our shared reference for “ewww”.
Is it...

Nope, wrong again.
How about...

Ah, yes there it is. A mentally retarded person. A person who is mentally late, mentally hindered. She, and all those like her, are the reference we share in order to comprehend the meaning of Emanuel's insult, “Fucking retarded.”
There is no “other context” for the put-down. Whenever you say “that’s retarded” or “Stop being retarded” you are referencing my youngest child. You are saying that something is stupid, like my daughter. That it is useless, like my daughter, worthless like my daughter.
The medical community (uh, unlike general society) has figured out the connection between the insult and the basis for our understanding of the insult, and they have moved to change the terminology used to describe people like my child. She is now intellectually disabled.
Do you know why they changed the terminology? Because mentally retarded people are not a synonym for stupid, or ineffective, or useless, or uncooperative, or worthless. So do them a favor and delete the slur “retard” from your vocabulary.
If you are not willing to do that, then maybe it is time to admit that something in your upbringing has retarded your sense of decency.