Y-axis
From Conservapedia
The y-axis is the vertical axis on a coordinate plane, as opposed to the horizontal axis, or x-axis. The point at which a line crosses the y-axis is referred to as the y-intercept.
The y-axis is the vertical axis on a coordinate plane, as opposed to the horizontal axis, or x-axis. The point at which a line crosses the y-axis is referred to as the y-intercept.