The Collaborative International Dictionary of English v.0.48:
Thwittle \Thwit"tle\, v. t. [See Thwite, and Whittle.] To cut or whittle. [Obs. or Prov. Eng.] --Palsgrave. [1913 Webster]The Collaborative International Dictionary of English v.0.48:
Thwittle \Thwit"tle\, n. A small knife; a whittle. [Written also thwitel.] [Obs.] "A Sheffield thwittle." --Chaucer. [1913 Webster]