1(A name given to) a fictitious or imaginary distant or foreign country, especially in Africa, typically depreciatively characterized as backward or primitive.
2With the. (A name for) an imaginary or hypothetical people, especially one used as the type of a little known society inhabiting a remote region. Also as a count noun: a member of such a supposed people.
3(A name for) an imaginary or hypothetical language, especially one used as the type of a little known language from a remote region. Also (derogatory) used as the type of an incomprehensible foreign language.
Of, relating to, or characteristic of a distant or foreign country, language, or people, especially in Africa or the developing world; specifically primitive, backward.
Early 20th century; earliest use found in American Antiquarian. Reduplication of an element of uncertain origin, perhaps the name of the Bongo people (from Bongo Bongo, self-designation: see note), probably reinforced (within English) by association with other similar-sounding words of African origin, e.g. Congo.