The Chinese word **岛屿 (dǎoyǔ)** for "island" is a **coordinative compound**, formed by combining two characters with closely related meanings: **岛 (dǎo)**, which means "island," and **屿 (yǔ)**, which specifically means "small island" or "islet." Together, they create a single, more general term that encompasses islands of all sizes, with the second character reinforcing and specifying the core concept of the first. This type of word formation, where two synonyms or near-synonyms are paired to form a single abstract or collective concept, is very common in Chinese vocabulary building.