Definition of insulator in US English:



  • 1A substance which does not readily allow the passage of heat or sound.

    ‘cotton is a poor insulator’
    • ‘Wool is fluffy and airy so it serves as an insulator to prevent the heat of the body from escaping.’
    • ‘Furthermore, their relative performance changes: down is a particularly poor insulator when wet, whereas other materials do not differ greatly when wet or dry.’
    • ‘A sunroom, or patio room has a lot of glass, and glass is a poor insulator.’
    • ‘An area of the turbo acts as an insulator from the exhaust heat to keep the intake air compressor side as cool as possible.’
    • ‘But the obese person in athletic competition is at great peril because the fat around his torso acts as an insulator, refusing to allow the body's heat to escape.’
    • ‘Since ice is an insulator, this will cause even more ice to form.’
    • ‘Cheap and fireproof, it was an all-purpose insulator used to lag buildings, railway carriages, even ironing boards.’
    • ‘If hindered from escaping by an insulator, the heat accumulates to a degree that can be exploited for generating electricity.’
    • ‘In fact, feathers on flightless birds, which merely need to be heat insulators rather than being amazingly designed aerodynamically, resemble hairs in shape as well.’
    • ‘Arctic and boreal mosses, for example, are effective insulators that minimize heat transfer from the soil surface to the underlying soil.’
    • ‘Did you know that overweight people tend to act as insulators and keep heat in?’
    • ‘This occurs when two different insulators, like skin and the polyester in a car seat, rub against each other, allowing electrons to flow from the skin into the polyester.’
    • ‘As a result, this coating is said to be useful for machining titanium and titanium alloys because it acts as an insulator, translating the high heat to the chip and not to the insert.’
    • ‘Asbestos cement is strong but lightweight, durable, waterproof, fireproof and a good insulator.’
    • ‘Wood floors not only look gorgeous, they are healthy, hard-wearing and warm because wood is a natural insulator.’
    • ‘Solid ice is a poor insulator, when compared to compressed snow.’
    • ‘The substance, widely used for many years as an insulator or flame retardant, causes several kinds of fatal pulmonary illness that can take decades to develop.’
    • ‘The air trapped between layers acts as an insulator to reduce heat transmission.’
    • ‘A good exhaust system is an excellent sound insulator and it also purifies the gases coming out of the engine.’
    • ‘It is also used as an insulator and for mixing with cement.’
    1. 1.1 A substance or device which does not readily conduct electricity.
      • ‘It can act as a conductor of electricity or an insulator.’
      • ‘The integrated circuit further includes an adhesive formed over the insulator.’
      • ‘Materials that do not allow for electrons to flow are called insulators.’
      • ‘PCBs were used as paint additives and as insulators in the electricity industry and although they were banned in 1970 are still present in water and soil from which they make their way into the food chain.’
      • ‘A semiconductor is a substance whose ability to conduct electricity is between that of an insulator like rubber and a full conductor like copper.’
      • ‘He suffered shock and serious burns when he touched the insulator.’
      • ‘Nineteen thirty-two also saw the introduction of a new handle material which was advertised to be tough, non-flammable and a perfect insulator against electricity.’
      • ‘A coating of a clear, conducting material makes the glass behave like a capacitor - a device that stores electrical charge between two conducting plates separated by an insulator.’
      • ‘We used these concepts to define conductors, insulators, and semiconductors, and showed one means of altering the conductivity of semiconductors.’
      • ‘When a voltage is applied across the sandwich, the hottest electrons ‘tunnel’ from the normal metal through the insulator to the superconductor.’
      • ‘Liam had climbed 30 ft up the pylon and came into contact with high voltage insulators.’
      • ‘By constructing the direct contact over an insulator, such as silicon dioxide, current leakage is minimized.’
      • ‘Unfortunately, existing dielectric insulators can't withstand the rigors of the aggressive chemical-mechanical polishing step used to produce a smooth copper surface.’
      • ‘This allows Motorola to shrink the insulators and so the size of the cell.’
      • ‘Zeng and his team reasoned that since boron and carbon are both insulators and sit next to each other on the periodic table, they might have similar growth patterns.’
      • ‘They lie in a grey area between conductors and insulators whose boundaries are somewhat unclear, and it is this ambiguity itself that is useful.’
      • ‘Substances with low capacitance are insulators.’
      • ‘Back in the 1970s, U.S. and Japanese researchers found that plastic - normally an insulator of electricity - could act as a conductor under certain circumstances.’
      • ‘Hendrik Schon claimed to have found a way of injecting electric charge into organic crystals, enabling him to turn insulators into conductors.’
      • ‘Unlike low-temperature superconductors, which are metals, high-temperature superconductors are insulators in their normal state.’
    2. 1.2 A block of material, typically glass or ceramic, enclosing a wire carrying an electric current where it crosses a support.
      • ‘On a hilltop at the edge of town, a bunch of drunken hunters were target-shooting at the ceramic insulators on Bishkek's primary high-voltage lines.’
      • ‘This painting portrays in great detail a skeleton-like electrical power transmission tower with dozens of identical ceramic insulators.’
      • ‘Just about everything is collectible these days, from ugly little dolls to colored glass insulators and medicine bottles.’
      • ‘In laparoscopic electrosurgical instruments, for instance, ceramics such as alumina and zirconia serve as insulators to protect surgeons from the electric current running through the device.’
      • ‘Glass telegraph insulators marked T.C.R. were one of the few things actually marked for the railway.’