banjo
['coil, spiral, volute, whorl, helix', 'binoculars, field glasses, opera glasses', 'bannister, banister, balustrade, balusters, handrail', 'ping-pong ball', 'backpack, back pack, knapsack, packsack, rucksack, haversack', 'hamper', 'book jacket, dust cover, dust jacket, dust wrapper']