The word 'streetlight' is a transparent English compound, formed by directly combining two native elements. The first part, 'street', originates from the Latin 'via strāta', meaning a road paved with stones, which entered Old English via Roman infrastructure. The second part, 'light', descends from the Proto-Germanic root 'leuhtą', related to brightness and vision. The compound logically denotes an artificial source of illumination specifically designed for a paved public road, reflecting its straightforward functional purpose from its constituent parts.

Structure: street (road) + light (illumination) - street: From Old English 'strǣt' (paved road), itself from Late Latin 'strāta (via)' meaning "paved (road)". In this compound, it functions as a noun specifying the location. - light: From Old English 'lēoht' (brightness, radiance), from Proto-Germanic 'leuhtą'. In this compound, it functions as a noun specifying the object's purpose.