The Special Olympics launched a campaign Tuesday to banish the word "retard," a casual insult that derives from an out-of-favor medical term and has long been considered inappropriate.

People signed pledges not to use the word and students gathered to denounce its use at rallies from Florida to Alaska. Over the long-term, organizers hope to change attitudes about people with mental disabilities, who number more than 190 million worldwide, according to the World Health Organization.

"It's insulting, it's painful and it hurts people," said actor Eddie Barbanell, who has Down syndrome and appeared in the movie "The Ringer." "Get that word out! End the word! Bury it!"

While "retard" itself was never a medical term, it derives from the phrase "mental retardation," which by around 1900 was commonly used by scientists and doctors, said Peter Berns, executive director of The Arc of the United States, a nonprofit advocate for those with intellectual and developmental disabilities.

Even though Berns said its pejorative connotation was established in the 1960s, the phrase "mental retardation" is still used in many state and federal laws, much to the dismay of those trying to stamp out its use.

"People with intellectual disabilities themselves really mounted a movement that they did not want to be referred to with the word 'retarded,"' he said.

As such, the American Association of Mental Retardation changed its name in 2007 to the American Association on Intellectual and Developmental Disabilities after its members pleaded for the organization to do so. In another sign that the formal use of the term "mentally retarded" had lost currency, The Associated Press replaced it in its stylebook in 2008 with "mentally disabled."

Still, those seeking to end the term's use face a difficult battle.

"This word is deeply ingrained in our psyche. It comes up in a lot of different contexts," said Andrew Imparato, president and chief executive officer of the American Association of People With Disabilities. "We have to kind of call it out and start a conversation about why it's not OK to use the word."

Among the signatures collected Tuesday were several that belonged to governors: In California, Gov. Arnold Schwarzenegger

— whose mother-in-law founded Special Olympics — signed a proclamation to stop using the word, as did Oklahoma Gov. Brad Henry, while Iowa Gov. Chet Culver issued a certificate of recognition in support of the campaign.

But the manpower behind the "Spread the Word to End the Word" campaign comes from the students who devised the campaign last month during a Special Olympics youth summit in Idaho and organized rallies around the country.

In Florida, 16-year-old Noah Gray organized a rally for some 600 students at Miami Palmetto Senior High School that featured a rap performance and a speech by Barbanell about his experiences of being called a "retard."

"Like many other high school students and adults, I used to use the word 'retarded' all the time," said Gray, who was invited to speak at last month's youth summit. "Since coming down from the Special Olympics, I have not used that word once ... and I'm discouraging other people" from using it.

At Bowie High School in Maryland, 18-year-old Shannan Barksdale helped gather 861 pledges that will be sent to the Special Olympics organization. During the school's lunch periods, Barksdale yelled, "Say no to the R-word!" and urged students to sign pledges.

"The word should be eliminated from everyone's vocabulary," she said.

Special Olympics has enlisted actor John C. McGinley of the TV show "Scrubs" as a spokesman for the campaign. McGinley, whose 11-year-old son has Down Syndrome. said many people don't realize the word is hateful.

"It is saturated in the vernacular, and this will take a while. And it's OK," he said Tuesday. "But it's important to get under way."