/ Dictionary / Index P propionibacterium: Meaning and Definition of Find definitions for: pro•pi•on•i•bac•te•ri•um Pronunciation: (prō"pē-on'u-bak-tēr'ē-um, -ō'nu-), [key] — pl. -te•ri•a any of several aerobic or anaerobic bacteria of the genus Propionibacterium, found in dairy products, esp. hard cheeses where certain species are associated with the ripening process. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. propionate propionic Related Content Daily Word Quiz: immense Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language