Source : Webster's Revised Unabridged Dictionary (1913)

Gradient \Gra"di*ent\, n.
   1. The rate of regular or graded ascent or descent in a road;
      grade.

   2. A part of a road which slopes upward or downward; a
      portion of a way not level; a grade.

   3. The rate of increase or decrease of a variable magnitude,
      or the curve which represents it; as, a thermometric
      gradient.

Gradient \Gra"di*ent\, a. [L. gradiens, p. pr. of gradi to step,
   to go. See {Grade}.]
   1. Moving by steps; walking; as, gradient automata.
      --Wilkins.

   2. Rising or descending by regular degrees of inclination;
      as, the gradient line of a railroad.

   3. Adapted for walking, as the feet of certain birds.

Source : WordNet®

gradient
     n 1: a graded change in the magnitude of some physical quantity
          or dimension
     2: the property possessed by a line or surface that departs
        from the horizontal; "a five-degree gradient" [syn: {slope}]