|psychiatry the condition of having a low intelligence quotient (below 70)|
mental retardation n.
Subnormal intellectual development or functioning that is the result of congenital causes, brain injury, or disease and is characterized by any of various deficiencies, ranging from impaired learning ability to social and vocational inadequacy. Also called mental deficiency.
Below-average intellectual ability resulting from a genetic defect, brain injury, or disease, and usually present from birth or early infancy.