/ Dictionary / Index G gas bacillus: Meaning and Definition of Find definitions for: gas' bacil"lus Pronunciation: [key] any of several pathogenic bacilli, esp. of the genus Clostridium, that produce gas in infected tissue. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. gas gasbag Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language