invasion of the body by pathogenic microorganisms the resulting condition in the tissues an infectious disease the act of infecting or state of being infected an agent or influence that infects persuasion or corruption, as by ideas, perverse influences, etc
WordReference Random House Learner's Dictionary of American English © 2026
in•fec•tion /ɪnˈfɛkʃən/USA pronunciation
n.
WordReference Random House Unabridged Dictionary of American English © 2026- the state of being infected:[uncountable]If you leave that wound untreated, infection will result.
- an infectious disease:[countable]an ear infection.
in•fec•tion
(in fek′shən),USA pronunciation n.
- an act or fact of infecting;
state of being infected. - Pathologyan infecting with germs of disease, as through the medium of infected insects, air, water, or clothing.
- an infecting agency or influence.
- Pathologyan infectious disease:Is this infection very dangerous?
- Pathologythe condition of suffering an infection.
- corruption of another's opinions, beliefs, moral principles, etc.;
moral contamination. - an influence or impulse passing from one to another and affecting feeling or action.
- Grammar(in Celtic languages) assimilation in which a vowel is influenced by a following vowel or semivowel;
umlaut.
- Late Latin infectiōn- (stem of infectiō). See infect, -ion
- Middle English infeccio(u)n 1350–1400
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