1. [n]  the value of a coordinate on the vertical axis
2. [v]  bring (components or parts) into proper or desirable coordination correlation; "align the wheels of my car"; "ordinate similar parts"
3. [v]  appoint to a clerical posts; "he was ordained in the Church"

1. \Or"di*nate\, a. [L. ordinatus, p. p. of ordinare. See
   {Ordain}.]
   Well-ordered; orderly; regular; methodical. ``A life blissful
   and ordinate.'' --Chaucer.
   {Ordinate figure} (Math.), a figure whose sides and angles
      are equal; a regular figure.
   

2. \Or"di*nate\, n. (Geom.)
   The distance of any point in a curve or a straight line,
   measured on a line called the axis of ordinates or on a line
   parallel to it, from another line called the axis of
   abscissas, on which the corresponding abscissa of the point
   is measured.
   Note: The ordinate and abscissa, taken together, are called
         co["o]rdinates, and define the position of the point
         with reference to the two axes named, the intersection
         of which is called the origin of co["o]rdinates. See
         {Coordinate}.
   

3. \Or"di*nate\, v. t.
   To appoint, to regulate; to harmonize. --Bp. Hall.
   

The y-coordinate on an (x,y) graph; the output of a function plotted against its input.

x is the "abscissa".

See Cartesian coordinates.