Flunk (flŭ&nsm;k), v. i. [imp. & p. p. Flunked (flŭ&nsm;kt); p. pr. & vb. n. Flunking.] [Cf. Funk.] To fail, as on a lesson; to back out, as from an undertaking, through fear.

Flunk, v. t. To fail in; to shirk, as a task or duty. [Colloq. U.S.]

Flunk, n. A failure or backing out; specifically (College cant), a total failure in a recitation. [U.S.]