huskhullchaff
FRcoquille · carapace · cosse · enveloppe
This kanji depicts a hard outer covering. It is frequently used in biological contexts for eggs or mollusks, such as kaigara for seashells or tamago no kara for eggshell. It can also be used metaphorically to describe breaking out of one's shell. It is not typically part of the core JLPT N1-N5 list.