Source : Webster's Revised Unabridged Dictionary (1913)

Orach \Or"ach\, Orache \Or"ache\, n. [F. arroche, corrupted fr.
   L. atriplex, Gr. ?. Cf. {Arrach}.] (Bot.)
   A genus ({Atriplex}) of herbs or low shrubs of the Goosefoot
   family, most of them with a mealy surface.

   {Garden orache}, a plant ({Atriplex hortensis}), often used
      as a pot herb; -- also called {mountain spinach}.

Source : WordNet®

garden orache
     n : Asiatic plant resembling spinach often used as a potherb;
         naturalized in Europe and North America [syn: {mountain
         spinach}, {Atriplex hortensis}]