knapple

from The Collaborative International Dictionary of English v.0.48

Knapple \Knap"ple\, v. i. [Freq. of knap, v., cf. D. knabbelen
   to gnaw.]
   To break off with an abrupt, sharp noise; to bite; to nibble.
   [Obs. or Prov. Eng.]
   [1913 Webster]