In Electricity, What's The Opposite Of A Conductor?

The opposite of a conductor (copper metal) is a insulator (plastic and rubber).  

Materials such as copper metal that conduct electricity (allow it to flow freely) are called conductors. Materials that don't allow electricity to pass through them so readily, such as rubber and plastic, are called insulators.

The opposite of a conductor is an insulator, such as rubber.

The opposite of a conductor is an insulator

conductor means where the electrical current flows freely

example: Copper

Insulator means where the electrical current cannot flow

example: Non-metallic solids