/ Thesaurus / M Synonyms of molecular weight Find synonyms for: Noun1. molecular weight, relative molecular mass, massusage: (chemistry) the sum of the relative atomic masses of the constituent atoms of a moleculeWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: fresco Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language