Definition of "infection"

infection

/ɪnˈfɛkʃən/

noun
countable and uncountable, plural infections
1. (pathology) The act or process of infecting.
2. An uncontrolled growth of harmful microorganisms in a host.
  Quotations
  An artificial kidney these days still means a refrigerator-sized dialysis machine. Such devices mimic […] real kidneys […] . But they are nothing like as efficient, and can cause bleeding, clotting and infection—not to mention inconvenience for patients, who typically need to be hooked up to one three times a week for hours at a time.
  2013 June 1, “A better waterworks”, in The Economist‎, volume 407, number 8838, page 5 (Technology Quarterly)
3. A disease caused by a pathogen.
4. A visible sign of such a disease, such as the suppuration of a wound.