/ Dictionary / Index B bacill-: Meaning and Definition of Find definitions for: bacill- Pronunciation: [key] a combining form ofbacillary. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Bach trumpet bacillary Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language