/ Dictionary / Index B bacillus Calmette-Guérin: Meaning and Definition of Find definitions for: bacil'lus Cal•mette'-Gué•rin' Pronunciation: (kal-met'gā-ran', -ran'), [key] a weakened strain of the tubercle bacillus, Mycobacterium bovis, used in the preparation of BCG vaccine. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. bacillus Bacillus thuringiensis* Related Content Daily Word Quiz: opulent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language