cyclopentanoperhydrophenanthrene UK /ˌsaɪkləʊˌpɛntənəʊˌpɜːhaɪdrəʊfəˈnænθɹiːn/US /ˌsaɪkloʊˌpɛntənoʊˌpəɹˌhaɪdɹoʊfəˈnænθɹiːn/ noun1 •The carbon skeleton found in steroids. More commonly known as gonane. formscyclopentanoperhydrophenanthrenes