The word **刷子 (shuāzi)**, meaning "brush," is a classic example of Chinese compound word formation through **morphological derivation**. It is formed by combining the root morpheme **刷 (shuā)**, which means "to brush" or "to scrub," with the extremely common and productive noun suffix **子 (zi)**. The suffix **子** here has no independent meaning but functions to nominalize the verb root, transforming the action into a concrete tool used to perform that action. Therefore, the structure follows the pattern of **Verb + 子**, resulting in a noun that signifies "an object for brushing."