1) Idiocy 
feeble-mindedness
Synonym: mental retardation. ... (05 Mar 2000) ... 
Type: Term Pronunciation: ol′i-gō-frē′nē-ă Synonyms: mental retardation
oligophrenia 1. Less than normal mental development. 2. Mental retardation; subnormal intellectual functioning which originates during the developmental period and is associated with impairment of one or more of the following: maturation, learning, social adjustment. Related 'few, small, less, litt...