The phrase "poor conductor" means someone or something that is not good at leading or guiding others or that does not allow electricity or heat to pass through easily. Full definition
Until now, metal - organic frameworks were considered poor conductors and not very useful for electrochemical reactions. (sciencedaily.com)
The PSRs are so frigid that regolith becomes an extremely poor conductor of electricity. (sciencedaily.com)
conductor — a material through which energy can be easily transferred as heat Gases are poor conductors because particles too far apart Liquids are decent conductors, but solids are the best because particles collisions occur more easily. (slideplayer.com)