conduit consisting of a long hollow object (usually cylindrical) used to hold and conduct objects or liquids or gases | a structure consisting of something wound in a continuous series of loops |
an electric railway operating below the surface of the ground (usually in a city) | reactor consisting of a spiral of insulated wire that introduces inductance into a circuit |
electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope | tubing that is wound in a spiral |
(anatomy) any hollow cylindrical body structure | a contraceptive device placed inside a woman's womb |
a hollow cylindrical shape | a transformer that supplies high voltage to spark plugs in a gasoline engine |
| a round shape formed by a series of concentric circles (as formed by leaves or flower petals) |