- infect (v.)

- late 14c., "fill with disease, render pestilential; pollute, contaminate; to corrupt morally," from Latin infectus, past participle of inficere "to stain, tinge, dye," also "to corrupt, stain, spoil," literally "to put in to, dip into," from in- "in" (see in- (2)) + facere "to make, do, perform" (see factitious). In Middle English occasionally in a neutral sense "tinge, darken," but typically used of things indifferent or bad, and especially of disease. Related: Infected; infecting.