D5305640 (dī-thī′ə-nīt′)n. The divalent anionic group S2O4, derived from dithionous acid, or a compound containing this group. Also called hydrosulfite.
dithionite
(daɪˈθaɪəˌnaɪt) n (Elements & Compounds) any salt of dithionous acid. Also called: hyposulphiteorhydrosulphite