Source : Webster's Revised Unabridged Dictionary (1913)

Grade \Grade\, n. [F. grade, L. gradus step, pace, grade, from
   gradi to step, go. Cf. {Congress}, {Degree}, {Gradus}.]
   1. A step or degree in any series, rank, quality, order;
      relative position or standing; as, grades of military
      rank; crimes of every grade; grades of flour.

            They also appointed and removed, at their own
            pleasure, teachers of every grade.    --Buckle.

   2. In a railroad or highway:
      (a) The rate of ascent or descent; gradient; deviation
          from a level surface to an inclined plane; -- usually
          stated as so many feet per mile, or as one foot rise
          or fall in so many of horizontal distance; as, a heavy
          grade; a grade of twenty feet per mile, or of 1 in
          264.
      (b) A graded ascending, descending, or level portion of a
          road; a gradient.

   3. (Stock Breeding) The result of crossing a native stock
      with some better breed. If the crossbreed have more than
      three fourths of the better blood, it is called high
      grade.

   {At grade}, on the same level; -- said of the crossing of a
      railroad with another railroad or a highway, when they are
      on the same level at the point of crossing.

   {Down grade}, a descent, as on a graded railroad.

   {Up grade}, an ascent, as on a graded railroad.

   {Equating for grades}. See under {Equate}.

   {Grade crossing}, a crossing at grade.

Grade \Grade\, v. t. [imp. & p. p. {Graded}; p. pr. & vb. n.
   {Grading}.]
   1. To arrange in order, steps, or degrees, according to size,
      quality, rank, etc.

   2. To reduce to a level, or to an evenly progressive ascent,
      as the line of a canal or road.

   3. (Stock Breeding) To cross with some better breed; to
      improve the blood of.

Grade \Grade\, n.
   A harsh scraping or cutting; a grating.

         The grade of hatchets fiercely thrown. On wigwam log,
         and tree, and stone.                     --Whittier.

Source : WordNet®

grade
     n 1: a body of students who are taught together; "early morning
          classes are always sleepy" [syn: {class}, {form}]
     2: a relative position or degree of value in a graded group;
        "lumber of the highest grade" [syn: {level}, {tier}]
     3: the gradient of a slope or road or other surface; "the road
        had a steep grade"
     4: one-hundredth of a right angle [syn: {grad}]
     5: a degree of ablaut [syn: {gradation}]
     6: a number or letter indicating quality (especially of a
        student's performance); "she made good marks in algebra";
        "grade A milk"; "what was your score on your homework?"
        [syn: {mark}, {score}]
     7: the height of the ground on which something stands; "the
        base of the tower was below grade" [syn: {ground level}]
     8: a position on a scale of intensity or amount or quality; "a
        moderate degree of intelligence"; "a high level of care is
        required"; "it is all a matter of degree" [syn: {degree},
        {level}]
     9: a variety of cattle produced by crossbreeding with a
        superior breed

grade
     v 1: assign a rank or rating to; "how would you rank these
          students?"; "The restaurant is rated highly in the food
          guide" [syn: {rate}, {rank}, {range}, {order}, {place}]
     2: level to the right gradient
     3: assign a grade or rank to, according to one's evaluation;
        "grade tests"; "score the SAT essays"; "mark homework"
        [syn: {score}, {mark}]
     4: determine the grade of or assign a grade to