- 1[transitive, intransitive] flunk (something) to fail an exam, a test, or a course I flunked math in fourth grade.
- 2[transitive] flunk somebody to make someone fail an exam, a test, or a course by giving them a low grade She's flunked 13 of the 18 students. Phrasal Verbsflunk out (of something)
NAmE//flʌŋk//(informal)Verb Forms present simple I / you / we / they flunk
he / she / it flunks
past simple flunked
-ing form flunking