simple past tense and past participle of grade
"The teacher graded all the exams before lunch."
In plain English: To grade something means to give it a score or rank based on how well it meets certain standards.
"The teacher graded all the exams before lunch."
arranged in a sequence of grades or ranks
"stratified areas of the distribution"
Having been smoothed by a grader.
"The freshly poured asphalt was graded to ensure a perfectly smooth driving surface."
In plain English: Graded means arranged into levels based on how good something is or how much of it there is.
"The graded report card showed that her math skills had improved significantly over the semester."