The Chinese word **巢穴 (cháoxué)** is a compound noun formed by combining two semantically related characters: **巢 (cháo)**, meaning "nest" (typically of birds or insects), and **穴 (xué)**, meaning "hole," "den," or "burrow" (typically of mammals or reptiles). Together, they create a single, more generalized concept meaning "lair," "hideout," or "den," referring to the dwelling place of an animal or, by metaphorical extension, the secret headquarters of a person or group. This formation follows a common pattern in Chinese where two words with similar or complementary meanings are joined to express a broader or more abstract idea—in this case, encompassing various types of animal dwellings and emphasizing a place of shelter and concealment.