/ Dictionary / Index C cobalt blue: Meaning and Definition of Find definitions for: co'balt blue' Pronunciation: [key] a deep blue to a strong greenish-blue color. any of a number of pigments containing an oxide of cobalt. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. cobalt bloom cobalt green Related Content Daily Word Quiz: belligerent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language