Definition of: streptococcus

(strep′tə·kok′əs) noun plural ·coc·ci (-kok′sī)
Any of a genus (Streptococcus) of Gram–positive, typically non–motile ovoid or spherical bacteria, grouped in long chains, and dividing in one plane, including highly pathogenic species causing many diseases, as pneumonia, erysipelas, etc. See illustration under BACTERIUM. [<NL <Gk. streptos twisted + coccus]
—strep′to·coc′cal (-kok′əl), strep′to·coc′cic (-kok′sik) adjective