What does infect mean?
To infect something is to introduce a harmful influence into it. Most commonly, the word refers to transmitting a disease-causing organism from one person, animal, plant, or object to another. It can also describe contaminating food, water, or air, corrupting a community or idea, or introducing malware into a computer or network. In medical usage, “infect someone with” identifies the pathogen being transmitted, while “be infected with” identifies the condition or organism affecting the subject. The word is used figuratively when something harmful spreads through language, behaviour, or information. Although “affect” can sound similar in some accents, it generally means to influence or alter something rather than to introduce disease or contamination. “Infect” is consequently a strong word for transmission and harmful introduction, ranging from clinical descriptions to metaphors about corruption and digital security.
verbTo cause someone or something to become affected by a disease-causing organism, especially by transmitting it. It can also mean to contaminate or corrupt something, or to introduce a harmful computer program into a system.
- To transmit a disease-causing organism to a person, animal, or plant.
- To contaminate food, water, air, or an object with harmful organisms or substances.
- To corrupt or taint an idea, community, or system through harmful influence.
- To introduce a harmful computer program into a computer or network.
"A careless cough can infect people nearby."
"Mosquitoes can transmit malaria and other diseases, although they do not infect people with all the pathogens they carry."
"The malicious attachment was designed to infect the computer with ransomware."
From the Latin inficere, “infect” literally meant “to put into” before developing its modern sense of introducing disease or contamination.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does infect come from?
The English verb comes from Latin inficere, formed from the prefix in- and the verb facere, meaning “to put into” or “to put something into someone or something.” In Latin, inficere developed the sense of introducing something harmful, especially poison or contamination. English borrowed the word for the transmission of disease and later extended it to figurative contamination and, in modern computing, the introduction of malicious software.
Related word forms
How infect is actually used
In medical and public-health contexts, “infect” is usually transitive and describes the transmission or introduction of a pathogen. The passive construction “be infected with” is common. In figurative and computing contexts, the word can imply contamination, corruption, or unauthorized intrusion.
Easily confused with infect
Infect means to introduce disease or contamination, whereas affect usually means to influence or alter something.