‘闭门’ literally means 'to close the door' — combining 闭 (bì, 'to close, shut') and 门 (mén, 'door'). As a verb phrase, it carries a figurative meaning: to withdraw from social interaction or public life, often for rest, study, reflection, or recovery. It implies intentional seclusion rather than mere physical door-closing.

This expression is commonly used in both formal and informal contexts — for example, when someone takes time off to focus on work or healing, or when a business temporarily suspends operations. While historically associated with scholarly seclusion (e.g., '闭门读书', studying alone at home), modern usage extends to health-related withdrawal (e.g., during illness) or digital detoxes. It’s not used for casual, short-term absences like stepping out for lunch; it suggests purposeful, sustained indoor seclusion.