grade

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A stage or degree in a process.
• noun A position in a scale of size, quality, or intensity.
• noun An accepted level or standard.
• noun A set of persons or things all falling in the same specified limits; a class.
• noun A level of academic development in an elementary, middle, or secondary school.
• noun A group of students at such a level.
• noun Elementary school.
• noun A number, letter, or symbol indicating a student's level of accomplishment.
• noun A military, naval, or civil service rank.
• noun The degree of inclination of a slope, road, or other surface.
• noun A slope or gradual inclination, especially of a road or railroad track.
• noun The level at which the ground surface meets the foundation of a building.
• noun A domestic animal produced by crossbreeding one of purebred stock with one of ordinary stock.
• noun Linguistics A degree of ablaut.
• intransitive verb To arrange in grades; sort or classify.
• intransitive verb To determine the quality of (academic work, for example); evaluate.
• intransitive verb To give a grade to (a student, for example).
• intransitive verb To level or smooth to a desired or horizontal gradient.
• intransitive verb To gradate.
• intransitive verb To improve the quality of (livestock) by crossbreeding with purebred stock.
• intransitive verb To change or progress gradually.

from The Century Dictionary.

• To sort out or arrange in order according to size, quality, rank, degree of advancement, etc.: as, to grade fruit, wheat, or sugar; to grade the children of a school.
• To reduce, as the line of a canal, road, or railway, to such levels or degrees of inclination as may make it suitable for being used.
• To improve the breed of. as common stock, by crossing with animals of pure blood.
• noun A step, degree, or rank in any series or order; relative position or standing as regards quantity, quality, office, etc.
• noun In a road or railroad, the degree of inclination from the horizontal; also, a part of such a road inclined from the horizontal. It is expressed in degrees, in feet per mile, or as a foot in a certain distance.
• noun In zoölogical classification, any group or series of animals, with reference to their earlier or later branching off from the stem or stock from which they are presumed to have evolved.
• noun An animal, particularly a cow or bull or a sheep, resulting from a cross between a parent of pure blood and one that is not pure-bred: as, an Aldevney grade. [Also used as an adjective.]
• noun In trigonometry, in the centesimal system, the hundredth part of a right angle: also, the hundredth part of a quadrant.
• noun A small difference between the brightness of two stars: substantially the same as a step: a term used by observers of variable stars.
• noun In philol., one of the positions or forms assumed by a vowel or root in a series of phonetic changes caused primarily by change of stress and other factors, as the vowels in English sing, sang, sung, ride, rode, ridden, etc., Latin capio, cepi, -cipio, etc., Greek √λειπ, √λιπ, √λοιπ, leave, √τεμ, √ταμ, √τομ, cut, etc.
• Same as graith.
• In physical geography, to develop by eroding or filling (degrading or aggrading) into an even slope on which an eroding and transporting agent (such as a stream) will not actively build up or wear down its course.
• In philology to alter or be altered by gradation or ablaut.
• To prove to be of a certain grade or quality.

from the GNU version of the Collaborative International Dictionary of English.

• transitive verb To arrange in order, steps, or degrees, according to size, quality, rank, etc.
• transitive verb To reduce to a level, or to an evenly progressive ascent, as the line of a canal or road.
• transitive verb (Stock Breeding) To cross with some better breed; to improve the blood of.
• noun A step or degree in any series, rank, quality, order; relative position or standing
• noun 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; ; a grade of twenty feet per mile, or of 1 in 264.
• noun A graded ascending, descending, or level portion of a road; a gradient.
• noun (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.
• noun 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.
• noun a descent, as on a graded railroad.
• noun an ascent, as on a graded railroad.
• noun See under Equate.
• noun a crossing at grade.