Staphylococcus, from Ancient Greek σταφυλή (staphulḗ), meaning "bunch of grapes", and κόκκος (kókkos), meaning "kernel" or "Kermes", is a genus of Gram-positive bacteria in the family Staphylococcaceae from the order Bacillales. Under the microscope, they appear spherical (cocci), and form in grape-like clusters. Staphylococcus species are facultative anaerobic organisms (capable of growth both aerobically and anaerobically).
The name was coined in 1880 by Scottish surgeon and bacteriologist Alexander Ogston (1844–1929), following the pattern established five years earlier with the naming of Streptococcus. It combines the prefix "staphylo-" (from Ancient Greek: σταφυλή, romanized: staphylē, lit. 'bunch of grapes'), and suffixed by the New Latin: coccus, lit. 'spherical bacterium' (from Ancient Greek: κόκκος, romanized: kókkos, lit. 'grain, seed, berry').