infect

verb

in·​fect in-ˈfekt 

infected; infecting; infects

transitive verb

1

: to contaminate with a disease-producing substance or agent (such as bacteria)

2

a

: to communicate a pathogen or a disease to

b

of a pathogenic organism : to invade (an individual or organ) usually by penetration

c

of a computer virus : to become transmitted and copied to (a device, such as a computer)

3

a

: contaminate, corrupt

the inflated writing that infects such stories

b

: to work upon or seize upon so as to induce sympathy, belief, or support

trying to infect their salespeople with their enthusiasm

infector

in-ˈfek-tər 

noun

Examples of infect in a Sentence

If you're sick you should stay home to avoid infecting other people in the office.

The virus has infected many people.

They were unable to prevent bacteria from infecting the wound.

Her enthusiasm has infected everyone.

The virus has infected many computers.

All the computers in the office were infected by the same virus.

Recent Examples on the Web

Serology measures antibodies formed against a specific pathogen. IgM antibodies indicate a new infection whereas IgG antibodies usually show that you have been infected in the past. —Tanya Feke, Verywell Health, 4 Apr. 2024

Most recently, a dairy worker in Texas was presumed to be infected by sick cattle, according to the CDC. —Youri Benadjaoud, ABC News, 3 Apr. 2024

The latest case – in a person in Texas who had exposure to dairy cattle presumed to be infected – was mild, officials said, but humans can get severely ill and die from the disease. —Jen Christensen, CNN, 3 Apr. 2024

Bird flu is widespread among wild birds in the U.S. and globally, and the pathogen was confirmed to have infected dairy cows in Texas and Kansas by the U.S. Department of Agriculture on March 25. —Eshaan Sarup, The Arizona Republic, 2 Apr. 2024

Dairy cows in five U.S. states have tested positive for bird flu, but your morning coffee probably doesn't have infected milk. —Mansee Khurana, NPR, 1 Apr. 2024

Texas health officials reported Monday that an individual who had been in contact with cattle has contracted H5N1 avian flu, only the second case ever recorded in the U.S. The cattle were presumed to be infected with the bird flu, the officials said. —Helen Branswell, STAT, 1 Apr. 2024

Sinclair had been in poor health for a number of years, including diabetes, and was admitted to the hospital during the weekend to treat a leg sore that had become infected and turned into sepsis. —Gary Graff, Billboard, 2 Apr. 2024

Saman Shafiq Less than a week after sick dairy cattle in Texas and Kansas tested positive for bird flu, Texas state officials reported that a person in the state has been infected with the virus after coming into close contact with the infected cows. —USA TODAY, 1 Apr. 2024

Word History

Etymology

Middle English infecten, enfecten "to inflict with disease, pollute, damage, corrupt," borrowed from Latin infectus, past participle of inficere "to dye, discolor, impregnate, taint, contaminate with disease," from in- in- entry 2 + facere "to make, bring about, perform, do" — more at fact

First Known Use

14th century, in the meaning defined at sense 2a

Phrases Containing infect

• co-infect

Kids Definition

infect

verb

in·​fect in-ˈfekt 

1

: to contaminate with a disease-producing substance or germ

infected bedding

2

a

: to pass a germ or disease to

coughing people who infect others

b

: to enter and cause disease in

bacteria that infect wounds

c

: to become copied to

a virus has infected the computer

3

: to cause to share one's feelings

infected everyone with his enthusiasm

infector

-ˈfek-tər 

noun

Medical Definition

infect

transitive verb

in·​fect in-ˈfekt 

1

: to contaminate with a disease-producing substance or agent (as bacteria)

2

a

: to communicate a pathogen or a disease to

b

of a pathogenic organism : to invade (an individual or organ) usually by penetration compare infest