D defs.my
Entry 1 sense Webster, 1913

Cobaltous

· Co·balt·ous · IPA
01 a. Pertaining to, derived from, or containing, cobalt; -- said esp. of cobalt compounds in which the metal has its lower valence.
  1. 1.
    Pertaining to, derived from, or containing, cobalt; -- said esp. of cobalt compounds in which the metal has its lower valence.(Chem.)
Phrases & compounds
Cobaltous chloride — a crystalline compound, CoCl2, of a pale rose color when hydrous, blue when dehydrated. Its solution is used for a sympathetic ink, the writing being nearly colorless when dried in the air, owing to absorbed moisture, and becoming bright blue when warmed.