noun
: a gummy substance that is obtained as a hygroscopic powder or a granular solid by reaction of alkali cellulose and sodium chloroacetate, that is either soluble in water or swells in water, and that is used chiefly as a thickening, emulsifying, and stabilizing agent (as in sizes for textiles and paper and in pharmaceutical ointments) and as a bulk laxative and antacid in medicine : a sodium salt of carboxymethyl cellulose