Dyllan Hildebrand, 17, of Bowie, Md., right, explains to a student why she should sign a pledge “not to say the R-word” Tuesday at Bowie High School in Bowie, Md. The pledge is part of a campaign by the Special Olympics to get people to stop using the word “retarded.”

Washington ? 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.”