in·​su·​la·​tor ˈin(t)-sə-ˌlā-tər How to pronounce insulator (audio)
: one that insulates: such as
: a material that is a poor conductor (as of electricity or heat) compare semiconductor
: a device made of an electrical insulating material and used for separating or supporting conductors

Examples of insulator in a Sentence

Metal is not a good insulator.
Recent Examples on the Web Columbia Sportswear, which is testing a metallic jacket fabric as a thermal insulator on the lander, will also take over the exterior of the Las Vegas sphere during the landing attempt, according to a press release. Eric Lagatta, USA TODAY, 25 June 2024 Engineers at Bell Labs realized that a specific kind of semiconductor—a material that carries electricity with an efficiency between that of a conductor such as copper and an insulator such as glass—can be used to detect light and, critically, record the value of an object’s brightness. Phil Plait, Scientific American, 7 June 2024 Down may be goose down (the premium insulator, according to Woodsen) or duck down (the clusters are smaller and less durable than goose, though still very good for insulation). Kathleen Felton, Better Homes & Gardens, 21 May 2024 Here, a tunneling electron microscope image shows a Josephson junction made with alpha-silicon insulator sandwiched between niobium titanium nitrite superconductors, achieving a critical dimension of 210 nanometers. Anna Herr, IEEE Spectrum, 15 May 2024 See all Example Sentences for insulator 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'insulator.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1801, in the meaning defined above

Time Traveler
The first known use of insulator was in 1801

Dictionary Entries Near insulator

Cite this Entry

“Insulator.” Dictionary, Merriam-Webster, Accessed 18 Jul. 2024.

Kids Definition


in·​su·​la·​tor ˈin(t)-sə-ˌlāt-ər How to pronounce insulator (audio)
: one that insulates
especially : a material that is a poor conductor of heat or electricity or a device made of such material

Medical Definition


in·​su·​la·​tor ˈin(t)-sə-ˌlāt-ər How to pronounce insulator (audio)
: a material that is used to provide insulation
also : a device made of such material

More from Merriam-Webster on insulator

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