hollow+cylinder
131Pump rod — Pump Pump, n. [Akin to D. pomp, G. pumpe, F. pompe; of unknown origin.] An hydraulic machine, variously constructed, for raising or transferring fluids, consisting essentially of a moving piece or piston working in a hollow cylinder or other… …
132Pump room — Pump Pump, n. [Akin to D. pomp, G. pumpe, F. pompe; of unknown origin.] An hydraulic machine, variously constructed, for raising or transferring fluids, consisting essentially of a moving piece or piston working in a hollow cylinder or other… …
