WordNet sense 1 (a bulging cylindrical shape; hollow with flat ends):

barrel

WordNet sense 2 (a cylindrical metal container used for shipping or storage of liquids):

metal drum

WordNet sense 3 (a musical percussion instrument; usually consists of a hollow cylinder with a membrane stretched across each end):

membranophone, tympan

WordNet sense 4 (a hollow cast-iron cylinder attached to the wheel that forms part of the brakes):

brake drum

WordNet sense 5 (small to medium-sized bottom-dwelling food and game fishes of shallow coastal and fresh waters that make a drumming noise):

drumfish

WordNet sense 6 (make a rhythmic sound):

beat, thrum

WordNet sense 7 (study intensively, as before an exam):

bone, cram, swot, get up, bone up, grind away, mug up, swot up