Any material that will readily release electrons is called:

A material that readily releases electrons is defined as a conductor. In electrical terminology, conductors have free electrons that can move easily throughout the material, allowing for the conduction of electric current. Metals such as copper and aluminum are prime examples of conductors due to their atomic structure, which facilitates the movement of electrons when a voltage is applied.

Conductors contrast with insulators, which do not allow electrons to move freely and thus do not conduct electricity. Resistors are materials that limit the flow of current and convert electrical energy into heat rather than facilitating the flow of electrons. Dielectrics are insulating materials that can store electrical energy when an electric field is applied. They do not readily release electrons like conductors do but instead, maintain their structure and prevent current from flowing through them.

In summary, the definition of a conductor aligns with the behavior of materials that readily release electrons, enabling them to conduct electricity efficiently.