mean current density

Defined as

$j = I A$

where $I$ is the electric current and $A$ is usually taken as the geometric area of the electrode. However the nature of the area used in this calculation must be clearly stated. In interpreting the mean current density it is important to know whether the current is uniformly distributed over the electrode interface.

Source:

PAC, 1974, 37, 499 (Electrochemical nomenclature) on page 513