Source : Webster's Revised Unabridged Dictionary (1913)

Diplococcus \Dip`lo*coc"cus\, n.; pl. {Diplococci}. [NL., fr.
   Gr. ? twofold + ? grain, seed.] (Biol.)
   A form of micrococcus in which cocci are united in a binary
   manner. See {Micrococcus}.

Source : WordNet®

diplococci
     See {diplococcus}

diplococcus
     n : gram-positive bacteria usually occurring in pairs
     [also: {diplococci} (pl)]