The compound 'white-light' is a modern English formation built from two fundamental Germanic roots. 'White' descends from the Proto-Germanic 'hwītaz', itself from the Proto-Indo-European root 'ḱweyt-', meaning 'to shine' or 'bright'. 'Light' comes from Proto-Germanic 'leuhtą', from the PIE root 'lewk-', meaning 'light' or 'brightness'. The term's literal meaning, describing light containing all visible wavelengths, emerged from the observation that such light appears white or colorless. Figuratively, it leverages the symbolic purity and clarity associated with 'white' to denote complete illumination of a subject, representing full understanding or revelation.

Structure: white (color) + light (illumination) white: From Old English 'hwīt', meaning bright, radiant, or the color of snow or milk. Its functional role is as an adjective modifying the noun 'light'. light: From Old English 'lēoht', meaning brightness, illumination, or the natural agent that makes things visible. Its functional role is as the core noun.