/ Thesaurus / A Synonyms of atomic number 21 Find synonyms for: Noun1. scandium, Sc, atomic number 21, metallic element, metalusage: a white trivalent metallic element; sometimes classified in the rare earth group; occurs in the Scandinavian mineral thortveititeWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: labyrinth Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language