flunked

simple past and past participle of flunk

(US, ambitransitive) Of a student, to fail a class; to not pass.
(US, transitive) Of a teacher, to deny a student a passing grade.
(US, broadly) To fail any challenge
(US, dated, informal) To shirk (a task or duty).
(US) To back out through fear. (Commonly in the phrase 'flunk it', the 'it' referring to a specific task avoided; sometimes without specific reference, describing a person's attitude to life in general.)