/ Dictionary / Index C cobaltous hydroxide: Meaning and Definition of Find definitions for: cobal'tous hydrox'ide Pronunciation: [key] a rose-red, amorphous, water-insoluble powder, CoO&multiplydot;3HO, used chiefly in the preparation of cobalt salts and in the manufacture of paint and varnish driers. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. cobaltous cobalt violet deep Related Content Daily Word Quiz: loathe Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language