gradient vs windrow

gradient

noun
  • A slope or incline. 

  • The ratio of the rates of change of a dependent variable and an independent variable, the slope of a curve's tangent. 

  • A differential operator that maps each point of a scalar field to a vector pointed in the direction of the greatest rate of change of the scalar. Notation for a scalar field φ: ∇φ 

  • A gradual change in color. A color gradient; gradation. 

  • The rate at which a physical quantity increases or decreases relative to change in a given variable, especially distance. 

  • A rate of inclination or declination of a slope. 

adj
  • Adapted for walking, as the feet of certain birds. 

  • Moving by steps; walking. 

  • Rising or descending by regular degrees of inclination. 

windrow

noun
  • A ridge or berm at a perimeter 

  • The green border of a field, dug up in order to carry the earth onto other land to improve it. 

  • A line of snow left behind by the edge of a snowplow’s blade. 

  • A long snowbank along the side of a road. 

  • A line of leaves etc heaped up by the wind. 

  • A similar streak of seaweed etc on the surface of the sea formed by Langmuir circulation. 

  • A line of gravel left behind by the edge of a grader’s blade. 

  • A row of cut grain or hay allowed to dry in a field. 

verb
  • To arrange (e.g. new-made hay) in lines or windrows. 

How often have the words gradient and windrow occurred in a corpus of books? (source: Google Ngram Viewer )