Source : Webster's Revised Unabridged Dictionary (1913)

Turpeth \Tur"peth\, n. [NL. turpethum, fr. Per. tirbid a
   cathartic, turbad a purgative root. Cf. {Turbith}.] [Written
   also {turbeth}, and {turbith}.]
   1. (Bot.) The root of {Ipom[oe]a Turpethum}, a plant of
      Ceylon, Malabar, and Australia, formerly used in medicine
      as a purgative; -- sometimes called {vegetable turpeth}.

   2. (Chem.) A heavy yellow powder, {Hg3O2SO4}, which consists
      of a basic mercuric sulphate; -- called also {turpeth
      mineral}.