Noun
z-direction
(algebraic geometry) The direction aligned with the z-axis of a coordinate system.
Magnetic or electric pinches main Z-Pinch : This method sends a strong current (in the z-direction) through the plasma. Source: Internet
This is most commonly seen in the z-direction, due to the conventional use of highly anisotropic voxels, which have a much lower out-of-plane resolution, than in-plane resolution. Source: Internet