Source : Webster's Revised Unabridged Dictionary (1913)

Thwaite \Thwaite\, n. (Zo["o]l.)
   The twaite.

Thwaite \Thwaite\, n. [CF. Icel. [thorn]veit a piece of land,
   fr. [thorn]v[=i]ta to cut. See {Thwite}, and cf. {Doit}, and
   {Twaite} land cleared of woods.]
   Forest land cleared, and converted to tillage; an assart.
   [Obs. or Prov. Eng.]

   Note: Thwaite occurs in composition as the last element in
         many names of places in the north of England; as, in
         Rosthwaite, Stonethwaite.