What is an example of a bad metal conductor?

The element mercury is one of the poorest conductors of the elemental metals. The alloy nickel-chromium (Nichrome) is very resistive and is used to construct the heating elements in many appliances incorporating a thermal source. Saying that a metal is a "bad conductor" can only be supported by a comparison. As thermal or electrical conductivity was not specified, we can only say that in metals, the effectiveness of a metal in conducting one is generally an indication of its effectiveness in conducting the other. Metals that conduct electricity well also usually conduct heat well.