/ Thesaurus / A Synonyms of atomic number 51 Find synonyms for: Noun1. antimony, Sb, atomic number 51, metallic element, metalusage: a metallic element having four allotropic forms; used in a wide variety of alloys; found in stibniteWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: kiln Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language