dink, n.³ — Green’s Dictionary of Slang

dink n.³

(US campus) failure to pass an examination.

1900

E.H. Babbitt ‘College Words and Phrases’ in DN II:i 32: dink, n. Failure to pass an examination.

in trouble, facing problems.

1904		R. McCardell Show Girl and Her Friends 115: It ain’t in New York alone that the drama’s on the dink.
1911		J. London ‘The Mexican’ in Complete Short Stories (1993) III 1992: Los Angeles must be on the dink when this is the best you can scare up .