the activity of supplying or providing something | conduit consisting of a long hollow object (usually cylindrical) used to hold and conduct objects or liquids or gases |
offering goods and services for sale | an electric railway operating below the surface of the ground (usually in a city) |
an amount of something available for use | electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope |
| (anatomy) any hollow cylindrical body structure |
| a hollow cylindrical shape |