The compound adjective "white-coated" is a transparent and relatively modern English formation. Its first element, "white," descends from the Proto-Germanic hwītaz, a term for brightness and light, which itself derives from the Proto-Indo-European root kweid-, meaning "to shine." The second element, "coat," entered English via Old French from the Latin cottus, meaning a tunic or military coat, likely of Celtic origin. The suffix "-ed," used to form participial adjectives, is of ancient Germanic lineage. The logic of the word is entirely literal and descriptive: it combines the color ("white") with a specific item of clothing ("coat") and adds an adjectival ending ("-ed") to denote the state of being clothed in such a garment. This straightforward compounding reflects a common pattern in English for creating occupational or descriptive labels, directly linking the visual uniform to the professional identity, most commonly associated with scientists, laboratory technicians, and medical professionals.

Structure: white (color) + coat (garment) + ed (adjective suffix) white: From Old English hwīt, meaning the color white. In this compound, it functions as an attributive noun modifying the type of coat. coat: From Old French cote, meaning a tunic or outer garment. In this compound, it is the core noun. ed: A suffix from Old English -ede, used to form adjectives from nouns, meaning "having the characteristics of" or "wearing."