A bulbous, immature chorionic villus that is formed of loose connective tissue with few fetal vessels. A chorionic immature intermediate villus develops from a chorionic mesenchymal villus, and is the forerunner of a chorionic stem villus. [ doi:10.1007/978-3-030-84725-8 http://www.ncbi.nlm.nih.gov/pubmed/487407 http://www.ncbi.nlm.nih.gov/pubmed/9260835 ]