grades

1. 1
   noun

   Plural of grade.

   Steep mountain roads have grades that challenge most heavy trucks.

   The mill sorts its lumber into several grades before shipping.

   Note

   A regular plural that gathers very different nouns under one spelling: a report card's marks, a road's slopes, a lumberyard's quality levels, the levels of schooling. The score and school-level meanings belong to US, Canadian and Philippine usage. The same spelling is also the verb form: a teacher grades papers, but a student gets grades. With the, it becomes the plural-only word for primary school.

2. 2
   verb

   Third-person singular simple present of grade.

   The professor grades on a strict curve every semester.

   Our new machine grades thousands of eggs an hour.

   Note

   A small form carrying a surprisingly technical verb. A teacher grades exams, and a road crew grades a surface with a grader. A dressmaker grades a seam by trimming its allowance to reduce bulk. A patternmaker grades a pattern up or down through sizes, and an annotator grades data by labeling it by hand. In every trade, the subject is he, she, it or a singular noun.

3. 3
   nounplural

   Grammar school or primary school: the years of schooling that come before high school.

   Most kids in our town learn to read while they are still in the grades.

   After thirty years in the grades, she finally moved up to teach high school.

   Note

   A plural-only noun that usually comes with the. Children are in the grades or finish the grades, and then go on to high school. Agnes Bostonne's "A Mother's Success Depends on her Daughters" (1926) draws exactly that line. Unlike the ordinary plural, it names the whole span collectively. One grade is a single year of school, while the grades are all those years taken together.

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