Definition of oligophrenia in English:

oligophrenia

Pronunciation /ˌɒlɪɡə(ʊ)ˈfriːnɪə/ /ɒˌlɪɡə(ʊ)ˈfriːnɪə/

noun

Psychiatry
  • Mental deficiency or retardation; an instance of this.

Origin

Late 19th century; earliest use found in Journal of Mental Science. From oligo- + ancient Greek ϕρήν mind + -ia, perhaps after paraphrenia.