/in fek"sheuhn/ , n.
1. an act or fact of infecting; state of being infected.
2. an infecting with germs of disease, as through the medium of infected insects, air, water, or clothing.
3. an infecting agency or influence.
4. an infectious disease: Is this infection very dangerous?
5. the condition of suffering an infection.
6. corruption of another's opinions, beliefs, moral principles, etc.; moral contamination.
7. an influence or impulse passing from one to another and affecting feeling or action.
8. Gram. (in Celtic languages) assimilation in which a vowel is influenced by a following vowel or semivowel; umlaut.
[ 1350-1400; ME infeccio ( u ) n infection- (s. of infectio ). See INFECT, -ION ]