in·​su·​la·​tor | \ ˈin(t)-sə-ˌlā-tər How to pronounce insulator (audio) \

Definition of insulator

: 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

With an inner steel bottle, outer steel bottle and vacuum between, the natural insulator doesn’t give cold—or heat—a medium to travel. Tim Newcomb, Popular Mechanics, "Why Are Hydro Flask Bottles Suddenly Everywhere?," 23 Feb. 2019 Panels of polycarbonate, acrylic and fiberglass are resilient, good insulators and have excellent light transmission, although fiberglass can discolor over time. Joseph Truini, Popular Mechanics, "How to Build a Greenhouse," 28 Jan. 2019 Under normal circumstances, the titanium/hafnium oxide layer would act like an insulator and block current flow at the intersection of the copper wires. John Timmer, Ars Technica, "Memristors built with 2-nanometer-thick parts," 14 Nov. 2018 High-intensity lasers can also turn electrical insulators into conductors, precisely cut or drill holes in many different materials, or perform laser eye surgery. Jennifer Ouellette, Ars Technica, "2018 physics Nobel Prize honors 3, including first woman in 55 years," 2 Oct. 2018 There was an earlier problem with an arcing insulator near the Stadium-Armory stop. Dana Hedgpeth, Washington Post, "Metro getting back to normal service, but delays remain," 23 Jan. 2018 Metro spokeswoman Sherri Ly said in an email that officials were investigating a reported arcing insulator. Dana Hedgpeth, Washington Post, "Metro restores service on Red Line in downtown Washington after debris fire," 1 June 2018 His first assignment was to run a ceramics division producing insulators and items used in scientific labs. James R. Hagerty, WSJ, "William Coors Steered Brewer While Fighting His Own Demons," 19 Oct. 2018 Here are a few trouble spots to look out for. Knob and tube wiring: Bare copper wires stretched from one porcelain insulator to another. Roy Berendsohn, Popular Mechanics, "The Smart Person's Guide To Avoiding Electrical Shock," 29 Apr. 2016

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'insulator.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of insulator

1801, in the meaning defined above

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Last Updated

13 Mar 2019

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Time Traveler for insulator

The first known use of insulator was in 1801

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English Language Learners Definition of insulator

: a material that allows little or no heat, electricity, or sound to go into or out of something


in·​su·​la·​tor | \ ˈin-sə-ˌlā-tər How to pronounce insulator (audio) \

Kids Definition of insulator

: a material (as rubber or glass) that is a poor conductor of electricity, heat, or sound


in·​su·​la·​tor | \ ˈin(t)-sə-ˌlāt-ər How to pronounce insulator (audio) \

Medical Definition of insulator

: a material that is used to provide insulation also : a device made of such material

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More from Merriam-Webster on insulator

Rhyming Dictionary: Words that rhyme with insulator

Spanish Central: Translation of insulator

Nglish: Translation of insulator for Spanish Speakers

Britannica English: Translation of insulator for Arabic Speakers Encyclopedia article about insulator

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