shell; husk; hull; pod; chaff
「殻」 has other readings with different meanings.
shell (e.g. electron shell)
chicken bones (e.g. for soup); chicken carcass
卵の殻をきれいに剥いて料理した。
I peeled the eggshell cleanly and cooked with it.
貝の殻を海辺で集めるのが趣味だ。
Collecting seashells is my hobby.
彼は自分の殻に閉じこもった。
He withdrew into his shell.