the area between the heart and the diaphragm, traditionally considered unreachable by medicine; also used to describe a terminal illness or deep-seated trouble when used in the phrase 病入膏肓 bìng​rù​gāo​huāng

Connects a describing word or phrase to the noun it describes, similar to 的 de but used in formal or literary writing.

(bound form) disease; illness; ailment; injury