Meaning

noun the pathological state resulting from the invasion of the body by pathogenic microorganisms

noun (phonetics) the alteration of a speech sound under the influence of a neighboring sound

noun (medicine) the invasion of the body by pathogenic microorganisms and their multiplication which can lead to tissue damage and disease

originFrom Old French infection, from Late Latin īnfectiō. Equivalent to infect + -ion.

Etymology from Wiktionary, CC BY-SA 3.0