[美]在同一水平面上

Grade \Grade\ (gr[=a]d), 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.