baggage car; luggage van
A railway car specifically for transporting luggage and parcels, not passengers. Common in older or traditional railway contexts.
In the old days, a baggage car was often coupled to trains at the station.
貨車 is a general freight car for goods, while 荷物電車 specifically refers to a baggage/luggage car, often part of a passenger train.
Compound of 荷物 (luggage) and 電車 (electric train), literally 'luggage electric train'. The exact historical derivation is uncertain, but it describes a dedicated car for baggage on electric railways.