/ Dictionary / Index B bacteroides: Meaning and Definition of Find definitions for: bac•te•roi•des Pronunciation: (bak"tu-roi'dēz), [key] — pl. -des. any of several rod-shaped, anaerobic bacteria of the genus Bacteroides, occurring in the alimentary and genitourinary tracts of humans and other mammals, certain species of which are pathogenic. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: bacteroides (Thesaurus) bacteroid Bactra Related Content Daily Word Quiz: pundit Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language