The word 'streetcar' is a transparent American English compound from the late 19th century, created to name a new mode of urban transport. Its first element, 'street', originates from the Old English 'strǣt', itself borrowed from Latin 'via strāta' meaning a road paved with stones, indicating the public thoroughfare on which it operates. The second element, 'car', has a long history tracing back to the Gaulish 'karros' via Latin 'carrus', referring to a wheeled wagon or chariot. The compound's logic is perfectly literal: a 'car' designed to run on 'streets', distinguishing it from railroad cars that operate on separate tracks.

Structure: street (public road) + car (vehicle) - street: From Old English 'strǣt', meaning a paved road, from Late Latin 'strāta (via)' meaning a paved (way). Its functional role is to specify the location or environment. - car: From Middle English 'carre', from Anglo-Norman, ultimately from Latin 'carrus', meaning a wheeled vehicle. Its functional role is to denote the type of object or vehicle.