Meaning of "Thwaites"

Hearne took the word "Thwayte" to signify "a wood grubbed up and turned into arable." His explanation, with other suggestions as to the meaning, of this word, may be found in a letter from Hearne to Mr. Francis Cherry, printed in vol. i. p. 194. of *Letters written by Eminent Persons in the Seventeenth and Eighteenth Centuries*, published by Longman and Co. in 1813.