奶 is a phono-semantic character: 女 on the left supplies the meaning category, while 乃 on the right mainly supplied the sound. Dictionaries record an older, more complex form, 嬭, and the familiar 奶 later became the everyday character for breast milk, milk and breastfeeding. It is therefore safer to read its parts as meaning plus sound than as a literal picture of a milk container. This seal-form-inspired sketch keeps a flowing 女 beside a curved 乃.
A piece of culture
From breakfast to a family table You will meet 奶 in everyday words such as 牛奶, “cow’s milk”, and 奶茶, “milk tea”. It also appears in family vocabulary: in Mandarin, 奶奶 commonly means a paternal grandmother, although the pronunciation and exact family terms differ across Chinese languages and regions. One small character can therefore connect a drink on the table with the way a family addresses an elder.