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., 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.
3. 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 Equate. Grade crossing, a crossing at grade.
Origin: Graded; grading.