retarded

1. (psychology, sometimes offensive, dated) Having mental retardation; mentally deficient or underdeveloped.Examples: "Experts in the field say there are now at least 200,000 retarded people over 60 in the United States."; "One day the order of things begins to unravel. First, the doctor, on horseback, is tripped up by an invisible wire and his injuries put him in the hospital for months. Then several children, including the son of the Baron and the retarded child of the doctor’s mistress, are severely beaten. Later, the Baron’s barn is set on fire."; "Shriver started the Special Olympics Games in 1968 to foster fitness and self-esteem for those with mental retardation and advocated in Washington for her cause well into her eighties. The event has grown to include 190 nations. Her concern for the mentally handicapped was attributed to her relationship with older sister Rosemary, who was said to have been mildly retarded and spent the majority of her life in a long-term care facility after a lobotomy."Synonyms: mentally retardeddatedoffensivesometimes

2. (psychology, sometimes offensive, dated) Specifically, having an IQ below 70.datedoffensivesometimes

3. (colloquial, derogatory, offensive) Extremely stupid; obtuseExamples: "Looking at Jack, Gabbie said, "What?" "That's the Troll Bridge." She groaned at the pun. "That's retarded.""; "I've got a terrific sign in front of my house that keeps intruders out: Retarded Pit Bull High on Angel Dust. No one's come over the wall yet. Except a couple of retarded guys who were high on angel dust."; "If it sounds like a bad script that a retarded child would write, it’s because it is. Yet, anti-Zionists will aggressively explain to you why this insanity makes perfect sense."colloquialderogatoryoffensive

4. (physics) Designating a parameter of an electromagnetic field which is adjusted to account for the finite speed of radiation.