nonconductor
non.con.duc.tor \.na:n-k*n-'d*k-t*r\ n : a substance that conducts heat, electricity, or sound only in very small degree
Webster's English Dictionarynon.con.duc.tor \.na:n-k*n-'d*k-t*r\ n : a substance that conducts heat, electricity, or sound only in very small degree