Dielectric (noun)

1. A material, such as a liquid, solid, or gas, that can be polarized by an applied electric field and is used in capacitors, transformers, and other electrical devices.
2. A dielectric material is an electrical insulator that can be polarized by an applied electric field, this polarization increases the electron density in the material and allows the material to store electrical energy in an electric field.

Origin:

Early 20th century: from dielectric + -ic.

Examples:

1. The most common dielectric materials are ceramics, plastics and glass.
2. The transformer oil is a liquid dielectric that helps to cool the transformer and insulate the windings.
3. Capacitors use dielectric materials to store electrical energy in an electric field.
4. The dielectric constant of a material determines how well it can store electrical energy.
5. The dielectric material used in the capacitor affects the capacitance of the device.