Flunk
Flunk (flunk) , intransitive verb
[Compare Funk.]
To fail, as on a lesson; to back out, as from an undertaking, through fear.
Flunk , transitive verb
1.
To fail in; to fail to pass (a test, examination, or course of study). [Colloquial United States]
2.
To shirk, as a task or duty.
Flunk , noun
A failure or backing out
a total failure in a recitation. [College cant; United States]