/ Dictionary / Index B borrelia: Meaning and Definition of Find definitions for: bor•rel•i•a Pronunciation: (bu-rel'ē-u, -rel'yu, -rē'lē-u, -rēl'yu), [key] — n. Bacteriol. any of several spiral, parasitic bacteria of the genus Borrelia, certain species of which are pathogenic for humans, other mammals, or birds. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: borrelia (Thesaurus) borough hall Borromini Related Content Daily Word Quiz: braggart Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language