noun
outer shell; crust
Refers to the hard outer covering of something, such as an egg, nut, crustacean, or the earth's crust. Often used in scientific or descriptive contexts.
卵の外殻を割る。
Crack the outer shell of the egg.
地球の外殻は地殻と呼ばれる。
The Earth's outer shell is called the crust.