chorionic villus
Medical term in embryology; refers to the tiny, finger-like projections of the chorion that facilitate nutrient and gas exchange between mother and fetus.
Chorionic villi play an important role in the formation of the placenta.
Compound of 絨毛膜 (chorion) + 絨毛 (villus). The exact historical derivation is uncertain; the spelling is conventionally associated with the medical meaning.