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

Soil acts as an insulator from temperature and holds moisture to protect the roots. — Erica Browne Grivas, Better Homes & Gardens, 6 May 2026

Authorities said a frozen layer of snow on top of the ice acts as insulator and prevents further freezing of the ice underneath. — Paul Burton, CBS News, 16 Feb. 2026

For decades, asbestos was a popular fire retardant and insulator in buildings, up until the 1970s. — Kenneth R. Gosselin, Hartford Courant, 24 Apr. 2026

Never let your man’s beverage get warm with Yeti’s sleek can insulator that maintains the liquid’s straight-out-of-the-cooler temperature even on the hottest of summer days. — Audrey Lee, Architectural Digest, 23 Mar. 2026

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