in·​su·​la·​tor | \ ˈin(t)-sə-ˌlā-tər \

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

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 The shape of the beeswax mimics the shape of high-voltage ceramic insulators Silva observed on Japanese power lines. Sharon Mizota,, "Eight ceramic octopus traps? Why Daniel Silva's show at Baert Gallery has us hooked," 23 June 2018 Jim also loved restoring antique cars and collecting bottles and insulators and always appreciated a great find. Hartford Courant,, "James Edward Darby Sr.," 17 June 2018 Ones like the Hitachiya Konro are made of diatomaceous earth brick, a natural insulator that keeps charcoal burning longer than other grills. Elaheh Nozari, Bon Appetit, "From Novice to Pitmaster, the Best Grills for Every Home Cook," 13 June 2018 How come the wetsuit isn’t the official state insulator? Norman Chad, San Antonio Express-News, "Chad: Surfing is not California’s state sport," 4 June 2018

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

16 Jan 2019

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Time Traveler for insulator

The first known use of insulator was in 1801

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More Definitions for insulator



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 \

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 \

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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