The Chinese word 蛋白质 (dànbáizhì) for "protein" is a three-character compound formed through descriptive morphological construction: 蛋 (dàn) means "egg", 白 (bái) means "white", and 质 (zhì) means "substance" or "quality". The term originated as a direct translation of the early scientific term "protein", which itself derives from the Greek proteios ("primary"), but was conceptually linked in Chinese to the most commonly observed and nutritionally significant source of protein, egg white. Thus, the compound literally means "egg-white substance", semantically capturing the essence of the nutrient by combining a familiar source (蛋 white), its distinguishing visual trait (白), and a suffix indicating a fundamental matter (质).