insulator

noun

in·​su·​la·​tor ˈin(t)-sə-ˌlā-tər 

: 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

Stopping this from happening is challenging, as most insulators fail at temperatures exceeding 2,732°F (1,500 °C). —Christopher McFadden, Interesting Engineering, 30 Aug. 2025

In Puerto Rico’s Sierra Bayamón neighborhood, a suspension insulator broke and a conductor fell to the ground because of inclement weather, Luma Energy said on Facebook. —Mirna Alsharif, NBC news, 17 Aug. 2025

Another is to act as an insulator, keeping heat from moving from the dark sheet to the light one, and thus enhancing the temperature gradient. —Andrew Cunningham, ArsTechnica, 14 Aug. 2025

Fortunately, snow, especially the light and fluffy kind, is a great insulator. —Paul Cappiello, The Courier-Journal, 2 July 2025

Word History

First Known Use

1801, in the meaning defined above

Rhymes for insulator

• activator
• actuator
• agitator
• alligator
• allocator
• alternator
• animator
• annotator
• applicator
• arbitrator
• aspirator
• aviator

Kids Definition

insulator

noun

in·​su·​la·​tor ˈin(t)-sə-ˌlāt-ər 

: 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 

: a material that is used to provide insulation

also : a device made of such material