Breadcrumb Home > Thesaurus > C Synonyms of cysteine Find synonyms for: Noun 1. cysteine, amino acid, aminoalkanoic acid usage: an amino acid containing sulfur that is found in most proteins; oxidizes on exposure to air to form cystine WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of cysteine (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Hanukkah Origins of the Christmas Holiday Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 Krampus: The Christmas Devil Kwanzaa ✖ Related Content Daily Word Quiz: anomie Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language