The word 枕头 is formed through a direct semantic combination of its two component characters: 枕 (zhěn), which means "to rest one's head upon", and 头 (tóu), which means "head". It illustrates a logical, conceptual fusion where the action or purpose (resting the head) is combined with the object of that action (the head itself) to name the resulting object, the item specifically designed for that purpose. Thus, the term literally and vividly means "head-rest-er", evolving naturally into its modern meaning of "pillow".