The Collaborative International Dictionary
Tetragonia expansa
Spinach \Spin"ach\, Spinage \Spin"age\, n. [OF. espinache, espinoche, F. ['e]pinard; cf. F. spinace, Sp. espinaca; all fr. Ar. isf[=a]n[=a]j, isfin[=a]j, aspan[=a]kh, probably of Persian origin.] (Bot.) A common pot herb ( Spinacia oleracea) belonging to the Goosefoot family.
Mountain spinach. See Garden orache, under Orache.
New Zealand spinach (Bot.), a coarse herb ( Tetragonia expansa), a poor substitute for spinach.
Note: Various other pot herbs are locally called spinach.