luggage rack(n = noun.artifact) roof rack - carrier for holding luggage above the seats of a train or on top of a car;
is a kind of carrier

bicycle rack, bomb rack, coat rack, dish rack, dress rack, hand luggage, luggage, luggage carousel, luggage carrier, luggage carrousel, luggage compartment, luggage van, magazine rack, music rack, pipe rack, plate rack, rack, rack and pinion, rack of lamb, rack railway, rack rent, rack up, roof rack, ski rack, spice rack, tie rack, towel rack