Meaning of “grade” - Learner’s Dictionary

grade

verb [ T ] us uk /ɡreɪd/
LEVEL

to separate people or things into different levels of quality, size, importance, etc:

The fruit is washed and then graded by size.
SCORE US UK mark

to give a score to a student's piece of work:

to grade work/papers

(Definition of “grade verb” from the Cambridge Learner’s Dictionary © Cambridge University Press)