in figurative use
A hard protective covering of bone or chitin, especially one which covers the dorsal portion of an animal.
Within any limits, enclosure, or substance; inside; internal; inner.
Remote from the limits, frontier, or shore; inland.
The set of all interior points of a set.
The inside regions of a country, distanced from the borders or coasts.
The inside of a building, container, cavern, or other enclosed structure.