Z-axis Definition
 zēăksĭs 
  z-axes
  
    noun
  
 In a three-dimensional Cartesian coordinate system, the axis that is perpendicular to the x-axis and the y-axis and that is used to measure or plot the values of z.
 Webster's New World 
Other Word Forms of Z-axis
Noun
Singular:
 z-axisPlural:
 z-axes




