1. Lack of normal development of intellectual capacities
   "The school provided special programs for students with mental retardation";
   - retardation [archaic], backwardness [archaic], slowness, subnormality [archaic]

Derived forms: mental retardations

Type of: daftness [informal], feeblemindedness, stupidity

Encyclopedia: Mental retardation, X linked, Marfanoid habitus