Pipe is a cylindrical TUBE used for a variety of purposes, such as plumbing, irrigation, and transportation of liquids and gases. SEWER is a pipe used to carry wastewater from buildings to a sewage treatment plant. CASK is a barrel-shaped container used to store liquids, such as wine or beer. KEG is a small barrel-shaped container used to store and transport beer. PASSAGE is a way through which something can pass, such as a tunnel or a pipe. PVC is a type of plastic commonly used to make pipes. DUCT is a TUBE or CONDUIT used to convey air, gas, or liquid. TUBE is a hollow cylinder used to transport liquids or gases. BRIAR and BRIER are both types of wood used to make pipes for smoking. ORGAN is a type of pipe instrument consisting of several ranks of pipes controlled by a keyboard. CONDUIT is a pipe or channel for conveying water or other fluid. Hollowtube is a type of pipe with an empty center, often used in plumbing.