shells
n. countable A2 Elementary US //ˈʃɛɫz// UK //ʃˈɛlz// shells
n. the hard outer parts that protect certain animals, like snails, crabs, or turtles. You also find them on eggs and nuts.
n. the hard, protective outer cases of molluscs, crustaceans, turtles, or eggs. Often used collectively to refer to the remains of these structures found on beaches.
The children collected colorful shells on the beach.
After the storm, the shoreline was covered in thousands of tiny white shells washed up by the tide.
Marine biologists study the composition of these calcium carbonate shells to understand how rising ocean acidity affects the health of local shellfish populations.
Usage
Commonly used in the plural when referring to a collection found in nature; the singular form often refers to the structure of a specific organism.