The Chinese word **母子** is a **compound word** formed by combining two independent characters: **母** (mǔ), meaning "mother," and **子** (zǐ), which in this context means "child" or "son." It follows a common structural pattern in Chinese where two related nouns are placed side-by-side to denote a close relationship or a pair, resulting in a meaning that is the sum of its parts—specifically, the "mother-and-child" relationship or pair. This method of word formation is typical for defining familial and social relationships.