a. Chem. [f. VANADIUM + -OUS c.] Containing vanadium in its lower valency, as opposed to VANADIC a.
1868. Watts, Dict. Chem., V. 988. Vanadious phosphate and sulphate have been obtained in definite crystals.
1870. Roscoe, in Lond. Philos. Mag., July, 63. Vanadious salt.
