Definition of dielectric in US English:



  • Having the property of transmitting electric force without conduction; insulating.

    • ‘The basic assumption is that electronic dielectric response is everywhere uniform.’
    • ‘An electrically polarizable object will be trapped in a region of a focused electric field, provided there is sufficient dielectric response to overcome thermal energy and the electrophoretic force.’
    • ‘The conductance caused by dielectric breakdown of membranes is proportional to the amplitude and duration of the electric field.’
    • ‘The accumulation of excessive electric charge in dielectric insulation is extremely rare, but when it does occur, it is often catastrophic.’
    • ‘Under normal circumstances, very few high-energy electrons lodge in the dielectric materials, and most naturally leak away over time.’


  • A medium or substance that transmits electric force without conduction; an insulator.

    • ‘The dielectric can be air, paper, plastic or anything else that does not conduct electricity and keeps the plates from touching each other.’
    • ‘In many photonic structures composed of two or more dielectrics, the absolute value of the refractive index contrast is critical to performance.’
    • ‘But low-k dielectrics improve the insulation between the circuits, thus allowing efficient transistor switching without the need for excessive power, and consequently without the extra heat.’
    • ‘This differs from the usual approach, which embeds the side chain directly within the protein dielectric.’
    • ‘At that size, it expects to make use of new materials and high-k dielectrics.’


Mid 19th century: from di- + electric, literally ‘across which electricity is transmitted (without conduction)’.