synchondrosis

noun
syn·​chon·​dro·​sis | \ ˌsin-ˌkän-ˈdrō-səs How to pronounce synchondrosis (audio) \
plural synchondroses\ -​ˌsēz How to pronounce synchondroses (audio) \

Medical Definition of synchondrosis

: an immovable skeletal articulation in which the union is cartilaginous