nonconductor

A material that conducts little or no electricity, heat, or sound.

A substance which does not conduct or transmit a particular form of energy (specifically, heat or electricity), or which transmits it with difficulty: thus, wool is a non-conductor of heat; glass and dry wood are non-conductors of electricity. See conductor, 6, electricity, and heat.

A substance which does not conduct, that is, convey or transmit, heat, electricity, sound, vibration, or the like, or which transmits them with difficulty; an insulator

any material that does not conduct electricity; a dielectric

a material such as glass or porcelain with negligible electrical or thermal conductivity