[ in-fekt ]
See synonyms for: infectinfectedinfecting on

verb (used with object)
  1. to affect or contaminate (a person, organ, wound, etc.) with disease-producing germs.

  2. to affect with disease.

  1. to taint or contaminate with something that affects quality, character, or condition unfavorably: to infect the air with poison gas.

  2. to corrupt or affect morally: The news of the gold strike infected him with greed.

  3. to imbue with some pernicious belief, opinion, etc.

  4. to affect with a computer virus.

  5. to affect so as to influence feeling or action: His courage infected the others.

  6. Law. to taint with illegality, or expose to penalty, forfeiture, etc.

verb (used without object)
  1. to become infected.

  1. Archaic. infected.

Origin of infect

1350–1400; Middle English infecten<Latin infectus (past participle of inficere to immerse in dye, discolor, taint, poison), equivalent to in-in-2 + -fec-, combining form of facere to do1, make (see fact) + -tus past participle suffix

Other words for infect

Other words from infect

  • in·fect·ant, adjective
  • in·fect·ed·ness, noun
  • in·fec·tor, in·fect·er, noun
  • non·in·fect·ed, adjective
  • non·in·fect·ing, adjective
  • pre·in·fect, verb (used with object)
  • re·in·fect, verb (used with object)
  • un·in·fect·ed, adjective

Words that may be confused with infect

Words Nearby infect Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use infect in a sentence

British Dictionary definitions for infect


/ (ɪnˈfɛkt) /

verb(mainly tr)
  1. to cause infection in; contaminate (an organism, wound, etc) with pathogenic microorganisms

  2. (also intr) to affect or become affected with a communicable disease

  1. to taint, pollute, or contaminate

  2. to affect, esp adversely, as if by contagion

  3. computing to affect with a computer virus

  4. mainly international law to taint with crime or illegality; expose to penalty or subject to forfeiture

  1. archaic contaminated or polluted with or as if with a disease; infected

Origin of infect

C14: from Latin inficere to dip into, stain, from facere to make

Derived forms of infect

  • infector or infecter, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012