肺脏 (fèi zàng) literally means 'lung organ' — 肺 (fèi) refers specifically to the lung, while 脏 (zàng) is a general term for internal organs, especially those in traditional Chinese medicine (TCM) and anatomical contexts. Together, 肺脏 emphasizes the lung as a vital, physical organ rather than just a functional concept. It is more formal and medically precise than the simpler word 肺 (fèi), which is commonly used in everyday speech, textbooks, and clinical settings.

This term appears frequently in medical reports, biology lessons, TCM discussions about organ systems, and health education materials. Unlike colloquial usage where people say ‘我的肺不好’ (My lungs aren’t good), 肺脏 tends to appear in structured descriptions like ‘肺脏结构’ (lung structure) or ‘肺脏功能’ (lung function). It carries a technical, objective tone and is rarely used in casual conversation or idioms.