The Chinese word 河流 (héliú), meaning "river", is a compound word formed through a semantic combination of two characters: 河 (hé), which specifically means "river", and 流 (liú), which means "to flow". In this modifier-head or subordinate compound structure, the second character 流 acts as the core semantic element (the "head"), defining the category as something that flows, while the first character 河 specifies the type of flowing body as a river, distinguishing it from other flows like air currents (气流) or electric currents (电流). This formation creates a precise and conceptually clear term that is more general than 河 alone, effectively capturing the essential characteristic of a river as a flowing watercourse.