Definitions of grade:

• noun:   a variety of cattle produced by crossbreeding with a superior breed
• noun:   the gradient of a slope or road or other surface

  Example: "The road had a steep grade"

• noun:   the height of the ground on which something stands

  Example: "The base of the tower was below grade"

• noun:   a degree of ablaut
• noun:   a relative position or degree of value in a graded group

  Example: "Lumber of the highest grade"

• noun:   a position on a scale of intensity or amount or quality
• noun:   a number or letter indicating quality (especially of a student's performance)

  Example: "Grade A milk"

• noun:   one-hundredth of a right angle
• noun:   a body of students who are taught together
• verb:   determine the grade of or assign a grade to
• verb:   assign a grade or rank to, according to one's evaluation

  Example: "Grade tests"

• verb:   level to the right gradient
• verb:   assign a rank or rating to
• name:  A surname (very rare: popularity rank in the U.S.: #51581)