The word **破旧 (pòjiù)**, meaning "dilapidated" or "old and worn-out," is a **compound word** formed by combining two independent characters with related meanings. The first character, **破 (pò)**, means "broken" or "damaged," while the second, **旧 (jiù)**, means "old" or "former." When combined in this **coordinative structure**, each character contributes its core meaning to create a new, unified concept that emphasizes a state of being both physically broken and aged, thus intensifying the overall sense of decay and shabbiness. This is a classic example of how modern Chinese frequently forms precise adjectives by pairing synonyms or near-synonyms.