a person who has flunked out of school or a course.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use flunkout in a sentence
The school is known in wealthy circles as “Dumb White Kids Getting High Together,” but Hilton actually managed to flunk out.
Most men do, I say, they usually work at it, study at it good enough so they don't flunk out.Warren Commission (2 of 26): Hearings Vol. II (of 15) | The President's Commission on the Assassination of President Kennedy
“To flunk out” is a vulgar expression for to retire through fear; the most that can be tolerated is, to sneak out.
"And if you don't want to flunk out you'd better be off to bed at once," Martin told him.Ye of Little Faith | Roger Phillips Graham
Other Idioms and Phrases with flunkout
Expel or be expelled from a school because one's work does not meet the required standard. For example, He flunked out of Harvard after just one year. [Slang; early 1800s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.