/ Dictionary / Index B bacterium: Meaning and Definition of Find definitions for: bac•te•ri•um Pronunciation: (bak-tēr'ē-um), [key] — n. sing. of Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: bacterium (Thesaurus) bacteriostat bacteriuria Related Content Daily Word Quiz: mamba Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language