See more synonyms for infect on
verb (used with object)
  1. to affect or contaminate (a person, organ, wound, etc.) with disease-producing germs.
  2. to affect with disease.
  3. to taint or contaminate with something that affects quality, character, or condition unfavorably: to infect the air with poison gas.
  4. to corrupt or affect morally: The news of the gold strike infected him with greed.
  5. to imbue with some pernicious belief, opinion, etc.
  6. to affect with a computer virus.
  7. to affect so as to influence feeling or action: His courage infected the others.
  8. 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
Related formsin·fect·ant, adjectivein·fect·ed·ness, nounin·fec·tor, in·fect·er, nounnon·in·fect·ed, adjectivenon·in·fect·ing, adjectivepre·in·fect, verb (used with object)re·in·fect, verb (used with object)un·in·fect·ed, adjective
Can be confusedafflict infect inflictinfect infest invest

Synonyms for infect

See more synonyms for on Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for infect

Contemporary Examples of infect

Historical Examples of infect

  • Throw me on a dunghill, and let me rot there, to infect the air!'

  • The nurse should be particularly careful not to infect herself.

    Rural Hygiene

    Henry N. Ogden

  • But you have no right to infect Bonaday, here, with your poison.

    Brother Copas

    Sir Arthur Thomas Quiller-Couch

  • They are easily caught by panic, lose their heads and infect all the others.

    Beasts, Men and Gods

    Ferdinand Ossendowski

  • Stand clear of rashness, and have nothing of insincerity or self-love to infect you.

    Dickory Cronke

    Daniel Defoe

British Dictionary definitions for infect


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
  3. to taint, pollute, or contaminate
  4. to affect, esp adversely, as if by contagion
  5. computing to affect with a computer virus
  6. 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
Derived Formsinfector or infecter, noun

Word Origin for infect

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

Word Origin and History for infect

late 14c., from Latin infectus, past participle of inficere "to spoil, stain," literally "to put in to, dip into," from in- "in" (see in- (2)) + facere "perform" (see factitious). Related: Infected; infecting.

Online Etymology Dictionary, © 2010 Douglas Harper

infect in Medicine


  1. To contaminate with a pathogenic microorganism or agent.
  2. To communicate a pathogen or disease to another organism.
  3. To invade and produce infection in an organ or body part.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.