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

Using gas as an insulator for spacecraft could replace traditional, single-use heat shields that burn away or the heat-resistant ceramic tiles that need to be replaced between flights, making spacecraft more fully and rapidly reusable, according to a statement from Texas A&M University. —Samantha Mathewson, Space.com, 11 May 2025

Myelin acts as an insulator that helps pass the brain’s electrical pulses between neurons safely and efficiently. —Monica Cull, Discover Magazine, 3 Apr. 2025

The revenues were derived from a commercial agreement with the Israel Electric Corporation for high-voltage insulator washing services. —Quartz Intelligence Newsroom, Quartz, 20 Mar. 2025

The Factorial product development team use an insulator in the lab. —IEEE Spectrum, 12 Mar. 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