Definition of coccus in English:


Pronunciation /ˈkäkəs/ /ˈkɑkəs/


  • Any spherical or roughly spherical bacterium.

    ‘Major and limb-threatening infections may involve aerobic gram positive cocci, gram negative bacilli, anaerobes, and enterococci.’
    • ‘Pathologic examination of the specimen revealed an organizing abscess with numerous bacterial cocci.’
    • ‘The elongation phase of growth distinguishes bacilli from cocci, which grow and divide by pure septation.’
    • ‘Penicillin kills most gram negative cocci that cause gonorrhea and epidemic spinal meningitis.’
    • ‘A gram-positive coccus was isolated from the bone marrow of a 5-year-old patient with leukemia.’


Mid 18th century (denoting a scale insect): modern Latin, from Greek kokkos ‘berry’. Compare with cochineal.