Noun
1. a structure consisting of something wound in a continuous series of loops;
"a coil of rope"2. a round shape formed by a series of concentric circles
3. a transformer that supplies high voltage to spark plugs in a gasoline engine
4. a contraceptive device placed inside a woman's womb
5. tubing that is wound in a spiral
6. reactor consisting of a spiral of insulated wire that introduces inductance into a circuit