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

These viruses typically spread among wild aquatic birds but can infect domestic poultry and other bird and animal species, according to the CDC. —Mary Kekatos, ABC News, 25 Apr. 2024

Only one person has been infected after exposure to sick cattle, and pink eye was their only symptom. —Will Sullivan, Smithsonian Magazine, 24 Apr. 2024

According to court documents, many of the crabs were infected with Bitter Crab Syndrome (BCS), a parasitic disease that is deadly to crabs. —Julia Daye, Sacramento Bee, 24 Apr. 2024

Since then, genetic data and investigations suggest the virus has spread to infect cows across at least eight states and a human dairy worker in Texas. —Alexander Tin, CBS News, 24 Apr. 2024

The seals may have been infected by living near or eating sick and dead birds. —Emily Anthes, New York Times, 22 Apr. 2024

After a record 613 days of being infected with a variant of COVID-19, a Dutch man has died at the age of 72. —Stacy Lambe, Peoplemag, 19 Apr. 2024

To date, a total of 12 people infected with the outbreak strain of salmonella have been reported from seven states. —Meghan Overdeep, Southern Living, 18 Apr. 2024

People infected with norovirus generally develop nausea, vomiting, diarrhea, stomach cramps, fever and body aches approximately 12 to 48 hours after consuming contaminated foods. —City News Service, San Diego Union-Tribune, 17 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