/ Thesaurus / A Synonyms of atomic number 27 Find synonyms for: Noun1. cobalt, Co, atomic number 27, metallic element, metalusage: a hard ferromagnetic silver-white bivalent or trivalent metallic element; a trace element in plant and animal nutritionWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: effervescent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language