/ Dictionary / Index P pneumococcus: Meaning and Definition of Find definitions for: pneu•mo•coc•cus Pronunciation: (n"mu-kok'us, ny"-), [key] — pl. -coc•ci a bacterium, Diplococcus pneumoniae, causing lobar pneumonia and associated with cerain other diseases, as pericarditis and meningitis. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: pneumococcus (Thesaurus) pneumobacillus pneumoconiosis Related Content Daily Word Quiz: frugal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language