dielectric
electrically poorly conducting or non-conducting, non-metallic substance in which charge carriers are generally not free to move
en-GB/daɪəˈlɛktɹɪk/
en-US/ˌdaɪɪˈlɛktɹɪk/
electrically poorly conducting or non-conducting, non-metallic substance in which charge carriers are generally not free to move