‘奶瓶’ literally combines 奶 (nǎi), meaning 'milk' or 'breast milk', and 瓶 (píng), meaning 'bottle'. Together, it refers specifically to a bottle designed for feeding infants—typically made of plastic, glass, or silicone, with a nipple attachment. It is an essential item in infant care and is used both for formula feeding and expressed breast milk.

This word is neutral in register and commonly used in daily life, parenting contexts, healthcare settings, and baby product discussions. Unlike generic terms like ‘瓶子’ (bottle), ‘奶瓶’ carries the specific functional meaning of 'baby bottle', emphasizing its purpose rather than just its shape or material. It appears frequently in baby registries, pediatric advice, and parenting blogs across Chinese-speaking communities.