Webster’s Revised Unabridged Dictionary · 1913
Orach
Or′ach, Or′ache, n. [F. arroche, corrupted fr. L. atriplex, Gr. ἀτράφαξος. 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.