In Electricity, the Opposite of a Conductor

This page is the CodyCross answer for the clue below from Inventions, Group 59, Puzzle 2.

Question is: In Electricity, the Opposite of a Conductor

and the answer is: INSULATOR

Word Meaning:

INSULATOR — A substance that does not transmit heat (thermal insulator), sound (acoustic insulator) or electricity (electrical insulator).

Definitions from Wiktionary.