Real Dictionary

gomphosis in American English
a form of immovable joint in which a bone or other hard part, as a tooth, fits into a socket
noun: an immovable articulation in which one bone or part is received in a cavity in another, as a tooth in its socket

gomphosis in British English
noun: a form of immovable articulation in which a peglike part fits into a cavity, as in the setting of a tooth in its socket