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

To observe the quantum mechanical motion of this macroscopic phase variable, the three scientists fabricated a device called the Josephson junction, which consists of two pieces of superconductors separated by an insulator layer thinner than 1/10,000 of a human hair. —Zhixin Wang, The Conversation, 10 Oct. 2025

But in the quantum world, matter takes on other forms – superconductors, magnets, topological insulators and, potentially, a slew of other states that non-quantum scientists haven’t even contemplated. —Andre Mouchard, Oc Register, 28 Sep. 2025

Wealth is an amazing insulator against reality, and yet, in an increasingly unequal world, viewers of all demographics have flocked to shows told from that point of view. —Thomas Page, CNN Money, 18 Sep. 2025

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

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