The Chinese word 主题曲 (zhǔtíqǔ), meaning "theme song," is a compound noun formed through semantic combination: 主题 (zhǔtí) means "main theme" or "subject," functioning as a modifier, and 曲 (qǔ) means "song" or "tune," serving as the head noun. Together, they create a precise meaning—"the song of the main theme"—following the common Chinese word-formation pattern where a descriptive element precedes the core noun it specifies. This structure efficiently conveys the concept of a musical piece that represents the central theme of a film, TV series, or other work.