a. Chem. [f. TUNGST(EN + -OUS c.] Applied to compounds in which tungsten combines as a tetrad, as tungstous chloride, WCl4, tungstous oxide, WO2. (Cf. TUNGSTIC.)
1860. in Mayne, Expos. Lex.
1868. Watts, Dict. Chem., V. 898. Tungsten forms two classes of compounds, in one of which it is tetratomic, and in the other hexatomic: Tungstous Chloride, WCl1; Tungstous Oxide, WO2.
