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 Ford stopped making trucks with the offending insulator by mid-November, according to the recall report filed with NHTSA. Laura Sky Brown, Car and Driver, 23 Dec. 2021 Plastic film insulator kits ($14, Target) are an even more budget-friendly seasonal solution. Maria V. Charbonneaux, Better Homes & Gardens, 10 Dec. 2021 Concrete is an effective insulator, but it can be coaxed into conducting electricity with the addition of a material called nanocarbon black. Justin Davidson, Curbed, 4 Dec. 2021 Down, made from clusters of duck or goose feathers, is a superior insulator while remaining breathable and lightweight. Washington Post, 4 Nov. 2021 Soil covers the top of the residence and surrounds it on three sides, serving as a natural insulator. Jack Flemming, Los Angeles Times, 18 Nov. 2021 The duff, with its compact but airy layering, is a superb insulator of frozen ground underneath. Randi Jandt, Scientific American, 1 Oct. 2021 Like silicon itself, silicon carbide is a semiconductor, meaning its properties lie between a material like copper that conducts electricity and an insulator like rubber that doesn’t. Yang Jie, WSJ, 7 Oct. 2021 Since plastic is an insulator, the static electricity can build up. Tim Johnson,, 29 Aug. 2021

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

Learn More About insulator

Time Traveler for insulator

Time Traveler

The first known use of insulator was in 1801

See more words from the same year

Dictionary Entries Near insulator




See More Nearby Entries 

Statistics for insulator

Last Updated

28 Jan 2022

Cite this Entry

“Insulator.” Dictionary, Merriam-Webster, Accessed 29 Jan. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

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 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

More from Merriam-Webster on insulator

Nglish: Translation of insulator for Spanish Speakers

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


Test Your Vocabulary

Name that Thing: Flower Edition

Name That Thing

Test your visual vocabulary with our 10-question challenge!

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

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