flunk /flʌŋk/ BrE AmE verb informal especially American English
[ Date: 1800-1900 ; Origin: Perhaps from flinch + funk 'to be afraid (of)' (18-21 centuries) ; ⇨ ↑ funk (2) ]
1 . [intransitive and transitive] to fail a test:
Tony flunked chemistry last semester.
2 . [transitive] to give someone low marks on a test so that they fail it SYN fail :
She hadn’t done the work so I flunked her.
flunk out phrasal verb informal especially American English
to be forced to leave a school or college because your work is not good enough
flunk out of
Ben flunked out of college.