The Collaborative International Dictionary of English v.0.48:

Misfall \Mis*fall"\, v. t. [imp. Misfell; p. p. Misfallen;
   p. pr. & vb. n. Misfalling.]
   To befall, as ill luck; to happen to unluckily. [Obs.]
   --Chaucer.
   [1913 Webster]