The Chinese word **姊妹 (zǐmèi)**, meaning "sisters," is a **compound word** formed by combining two semantically related characters: **姊 (zǐ)**, which specifically means "older sister," and **妹 (mèi)**, which means "younger sister." This structure follows a common pattern in Chinese lexicon where two terms from the same category are joined to create a single, broader term that encompasses the entire category—in this case, the general concept of sisters regardless of birth order. The word exemplifies a **coordinative compound**, where both elements are of equal syntactic importance and together express a collective meaning.