What is the definition of an ohmic conductor?

An ohmic resistor is a resistor that obeys Ohm's law, and a non-ohmic one dose not. All resistors resistance will begin to change as there temperature changes, and often we need a resistor with a steady resistance, thus some resistors, which we refer to as ohmic, will disperse the heat being generated and therefore it will keep a steady resistance. Resistors that do not disperse their heat will have varying resistances and therefore are non ohmic.

Ohms law, named after the German physicist Georg Ohm, states that the current through a conductor, between two points, is directly proportional to the potential difference (voltage) across the two points, and inversely proportional to the resistance between them.

~Ben Frilay-Cox