The word 唾液 (tuòyè), meaning "saliva," is a modern Chinese compound formed by combining two morphemes: 唾 (tuò), which historically means "to spit" or "spittle," and 液 (yè), which means "liquid" or "fluid." It is constructed using a modifier-head structure common in Chinese, where the first character 唾 specifies the type (spittle-related) and the second character 液 categorizes it as a bodily fluid. This formation creates a precise, technical term for the fluid secreted in the mouth, paralleling the way many scientific or medical terms are systematically built in the language.