/ Dictionary / Index C coliform bacillus: Meaning and Definition of Find definitions for: col'iform bacil'lus Pronunciation: [key] — Bacteriol. Bacteriol. any of several bacilli, esp. Escherichia coli and members of the genus Aerobacter, found as commensals in the large intestine of humans and certain other animals, the presence of which in water indicates fecal pollution. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. coliform Coligny Related Content Daily Word Quiz: drowsy Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language