insulator

noun

in·​su·​la·​tor ˈin(t)-sə-ˌlā-tər How to pronounce insulator (audio)
: one that insulates: such as
a
: a material that is a poor conductor (as of electricity or heat) compare semiconductor
b
: 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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
With regard to the oil inside the pole's transformer, the oil acts as an insulator for the electrical current in the transformer that generates heat. — Tara Molina, CBS News, 6 Aug. 2026 The result was an insulator-free topological waveguide with four parallel unidirectional channels, including two channels carrying signals in each direction, all packed tightly together without sacrificing robustness. — Rupendra Brahambhatt, Interesting Engineering, 1 Aug. 2026 The architects used building materials like bricks made of crushed sand and ash residue that have been found to be effective insulators, deflecting heat. — Kamala Thiagarajan, NPR, 1 Aug. 2026 An available cotton interior insulator is sold separately for those who want extra warmth. — New Atlas, 27 July 2026 See All Example Sentences for insulator

Word History

First Known Use

1801, in the meaning defined above

Time Traveler
The first known use of insulator was in 1801

Rhymes for insulator

See All Rhymes for insulator

Browse Nearby Words

insulative
insulator
insulin
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Cite this Entry

“Insulator.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/insulator. Accessed 10 Aug. 2026.

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Kids Definition

insulator

noun
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

insulator

noun
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

Nglish: Translation of insulator for Spanish Speakers

Britannica.com: Encyclopedia article about insulator

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