Shell was a word used to describe a type of organic matter or something inorganic that had a similar structure.
For example, a turtle's anatomy consisted of a shell, which functioned as a protective armor. Clamshells served a similar function.
Also, an amphibian, bird or reptile's embryo developed inside an eggshell, and peanuts and certain other types of fruits also had shells.
- ↑ As seen in the opening theme of The All-New Super Friends Hour (1977).