Semi-Bantu or Semibantu is a non-genealogical term that refers to those African languages spoken by the inhabitants of the Western grassfields of Cameroon (portions of the Adamawa, West, Northwest, and Southwest provinces) which are Bantoid languages but don't belong to the Bantu languages.
These languages have been influenced by the languages of both Bantu-speaking ethnic groups in the forests to the south and of the Benue-Congo-speaking peoples of the savannas to the north.
The three major ethnic groupings who speak Semi-Bantu languages in Cameroon are the Bamileke, Bamum, and Tikar. The three groups share many similarities of culture and may come from a common ancestral people.
References
Semi-Bantu Wikipedia(Text) CC BY-SA