/ Dictionary / Index S sulfamethoxazole: Meaning and Definition of Find definitions for: sul•fa•meth•ox•a•zole Pronunciation: (sul"fu-meth-ok'su-zōl"), [key] — n. Pharm. an antimicrobial substance, CHNOS, used against a variety of susceptible Gram-positive and Gram-negative organisms, as in the treatment of certain urinary tract infections and skin infections. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: sulfamethoxazole (Thesaurus) sulfa drug Sulfamylon Related Content Daily Word Quiz: voracious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language