A category of bacteria that can cause boils, blood poisoning, and other serious infections.
staphylococcus staph·y·lo·coc·cus (stāf'ə-lō-kŏk'əs)
n. pl. staph·y·lo·coc·ci (-kŏk'sī, -kŏk'ī)
A spherical gram-positive parasitic bacterium of the genus Staphylococcus, usually occurring in clusters and causing boils, septicemia, and other infections.