The precursor to the baozi, the Mántóu, 蠻頭, later evolved into the present day 饅頭. According to De Bao Xu, a professor in the Chinese department at Hamilton College, the Chinese changed the characters to denote mantou because the original characters “sounded too savage.” The characters for “mantou” contain a radical on the left that denotes food, a middle character that means “head”, and a suffix on the right.
For hundreds of years, mantou indicated both stuffed and unstuffed steamed buns. It was not until the Song Dynasty (960-1279 CE) that the word baozi came into use to indicate stuffed buns, and mantou increasingly became used to denote unstuffed buns only.
Baozi, is denoted in Mandarin as: 包子. The first character, 包, “bao,” translates to “wrapping, pack, bundle, or package.” This is an explicit reference to the dumpling’s wrapped shape, and also alludes to the technique necessary for assembling the baozi. Interestingly enough, the word “bao” can be represented with a variety of pictograms that have subtle differences in meaning. Some include: 胞, which denotes womb, placenta, or fetal membrane; 裏, which denotes inside, interior, or “within”; or 苞, which denotes firm, enduring, or bursting forth. This last character that means “bao”, which alludes to the interior nature of wrapped things, contrasts with the character used for “bao” in baozi, 包, which suggests the package-like nature of the dumpling.
The second pictogram, 子, looks like an image of a baby with its arms spread wide. When alone, the pictogram can indicate son, baby, or derivative. The use of such a character in the word for baozi seems appropriate due to the wrapped, or swaddled nature of dumplings. The etymology of baozi gives no indication of the filling, ingredients of the wrapping, or on the method of cooking; the term simply relates the shape and general components of the dumpling.