noun
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.
絨毛膜絨毛は胎盤の形成に重要な役割を果たす。
Chorionic villi play an important role in the formation of the placenta.
絨毛膜 is the 'chorion' (the outermost fetal membrane), whereas 絨毛膜絨毛 are the villi that grow from it.
Compound of 絨毛膜 (chorion) + 絨毛 (villus). The exact historical derivation is uncertain; the spelling is conventionally associated with the medical meaning.