‘乳母’ (rǔ mǔ) literally combines ‘乳’ (rǔ), meaning ‘milk’ or ‘breast’, and ‘母’ (mǔ), meaning ‘mother’. Together, it refers specifically to a woman who breastfeeds and cares for another woman’s infant—commonly known in English as a ‘wet nurse’. Historically, wet nurses were employed by families who could not or chose not to breastfeed their own children, especially among royalty or affluent households in imperial China. The term carries formal, somewhat literary connotations and is rarely used in modern daily speech.

Unlike general childcare terms like ‘保姆’ (bǎomǔ, nanny), ‘乳母’ emphasizes the biological function of lactation and early infant nourishment. It appears primarily in historical texts, period dramas, or discussions of traditional childcare practices. While the role has largely been replaced by formula feeding and professional pediatric care, the word remains culturally significant for understanding family structures and social hierarchies in pre-modern Chinese society.