- a material of such low conductivity that the flow of current through it is negligible.
- insulating material, often glass or porcelain, in a unit form designed so as to support a charged conductor and electrically isolate it.
Examples from the Web for insulator
The top of each casting is smaller in diameter than the hole in the insulator, and is grooved so as to hold the cement.
No matter how perfectly it might be insulated, the atmosphere itself would not be an insulator, with power such as this.Empire|Clifford Donald Simak
Moisture will allow some current to pass over the surface of any substance no matter how good an insulator it may otherwise be.Motion Picture Operation, Stage Electrics and Illusions|Henry C. Horstmann
To reach the cross-arm, the electric current passes down over the wet or dirty outside surface of the insulator to its lower edge.
In electrical engineering, paper as an insulator is almost indispensable.From Paper-mill to Pressroom|William Bond Wheelwright
British Dictionary definitions for insulator
Science definitions for insulator
Culture definitions for insulator
A material that does not easily transmit energy, such as electric current (see also current) or heat. Materials such as wood, plastic, and ceramics are insulators. Fiberglass is an example of a heat insulator. (Compare conductor.)