'Grade crossing' definitions:

Definition of 'grade crossing'

noun

Intersection of a railway and a road on the same level; barriers close road when trains pass [syn: level crossing, grade crossing]

From: GCIDE

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. [1913 Webster]
They also appointed and removed, at their own pleasure, teachers of every grade. --Buckle. [1913 Webster]
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. [1913 Webster]
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. [1913 Webster]
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. [1913 Webster]