Insulator
Part of speech: noun
Definition: A substance that does not transmit heat (thermal insulator), sound (acoustic insulator) or electricity (electrical insulator). insulator A non-conductive structure, coating or device that does not transmit sound, heat or electricity (see image)
Dielectric
Part of speech: noun
Definition: An electrically insulating or nonconducting material considered for its electric susceptibility, i.e. its property of polarization when exposed to an external electric field.
Part of speech: adjective
Definition: (electrically) insulating