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Webster 1913 Edition

Noun.

[See

, and

(Biol.)

A form of micrococcus found in the sputum (and elsewhere) of persons suffering with pneumonia, and thought to be the cause of this disease.

pneumococcus ‎(plural pneumococci)

A gram-positive bacterium, Streptococcus pneumoniae, that causes pneumonia and other infectious diseases

Streptococcus pneumoniae