/ Dictionary / Index E ethambutol: Meaning and Definition of Find definitions for: eth•am•bu•tol Pronunciation: (e-tham'byu-tôl", -tol"), [key] — n. Pharm. an antimicrobial substance, CHNO, active against susceptible bacteria of the genus Mycobacterium, in the treatment, in combination with other drugs, of tuberculosis. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ethal Ethan Related Content Daily Word Quiz: soporific Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language