flunk out

verb2

1. •
   To fail to finish school, or a given subject, program or course, due to academic shortcomings; i.e., to have too many flunking or failing grades (marks).

   • He flunked out of high school as a youth, but finished school later in life.
2. •
   (of an educator or institution) To impose failing grades on (a student), often requiring a retaking of the course or academic year.