Definition for Gradient
From Biology Forums Dictionary
1) A slope, which may be upward or downward.
2) The degree of steepness or inclination, e.g., of a road or other geographic features.
3) The rate of change of one variable relative to another, e.g. a physical quantity (e.g. temperature or pressure) increases or decreases relative to change in a given variable (e.g. distance).
4) The rate of change in growth, metabolism, or physiological activity of a cell or organism.
