/ Dictionary / Index N nalidixic acid: Meaning and Definition of Find definitions for: na'li•dix'ic ac'id Pronunciation: (nā'li-dik'sik, nā"-), [key] — Pharm. Pharm. a substance, CHNO, that has antibacterial activity against many susceptible Gram-negative organisms, esp. used in the treatment of urinary tract infections. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. naled Nalline Related Content Daily Word Quiz: banshee Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language