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

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 Arcing happens when something like debris or a worn-out cable on an insulator allows the current that helps run the trains to break free. Dana Hedgpeth, Washington Post, "Metro restores service on Red Line in downtown Washington after debris fire," 1 June 2018 After all, the behavior of the electrons in a material determines its properties as a whole—whether the substance is a metal, an insulator, a magnet, or something else. Neil Savage, Scientific American, "What Are the Limits of Manipulating Nature?," 8 May 2018 More than 35 sales tables will feature all types of collectibles, with an emphasis on antique insulators and related items such as old telephones and lightning rod equipment. Courant Community, "Community News For The Enfield Edition," 3 Apr. 2018 Mueller became famous for designing the alligator clip, which became his business--producing about 100,000 clips and 33,000 insulators daily in the '60s. Anne Nickoloff,, "Historic electric building reinvented as Mueller Lofts: Apartment of the week," 11 Apr. 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.

See More

First Known Use of insulator

1801, in the meaning defined above

Keep scrolling for more

Learn More about insulator

Statistics for insulator

Look-up Popularity

Time Traveler for insulator

The first known use of insulator was in 1801

See more words from the same year

Keep scrolling for more

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

Keep scrolling for more

Comments on insulator

What made you want to look up insulator? Please tell us where you read or heard it (including the quote, if possible).


to reject or criticize sharply

Get Word of the Day daily email!

Test Your Vocabulary

Words from Greek and Roman Mythology Quiz

  • the-triumph-of-venus-by-alessandro-magnasco
  • Boreal comes from the name of the ancient Greek god of which wind?
Spell It

Can you spell these 10 commonly misspelled words?

Bee Cubed

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!