misgrade

/mɪsˈɡreɪd/
verb
  1. To give a wrong grade or score to a student, test, or piece of work.
    • The teacher realized she had misgraded several exams and corrected them.
    • He was upset because the system misgraded his math test due to a scanning error.
    • If the computer misgrades your essay, you can request a manual review.
Synonyms
Antonyms