The Collaborative International Dictionary of English v.0.48:

Turnwrest \Turn"wrest`\ (t[^u]rn"r[e^]st`), n.
   (a) Designating a cumbersome style of plow used in England,
       esp. in Kent.
   (b) Designating a kind of hillside plow. [Eng.] --Knight.
       [1913 Webster]