y-Axis

y-axis - 

(1) [coordinate systems] In a planar coordinate system, the vertical line that runs above and below (north and south of) the origin (0,0). Numbers north of the origin are positive, and numbers south of it are negative.

(2) [coordinate systems] In a spherical coordinate system, a line in the equatorial plane that passes through 90 degrees east longitude.

(3) [mathematics] On a chart, the vertical axis.

[Category=Geospatial ]

Source: esri, 16 October 2012 09:18:59, http://support.esri.com/en/knowledgebase/GISDictionary/term/abbreviation