The word 裙子 is formed by combining the character 裙 (qún), which specifically means "skirt", with the character 子 (zi), a very common and often meaningless suffix added to many nouns in Chinese. Adding 子 to 裙 does not change its core meaning; instead, it follows a standard pattern for creating a familiar, everyday noun, making the word sound more complete and natural in speech, much like how "-er" can be added to "skirt" in English to make "skirter", though in Chinese this process is grammaticalized and essential.