infected; infecting; infects
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
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
One reason may be that H5N1 is clumsy at infecting people.
—
Brenda Goodman, CNN, 6 Feb. 2025
In most people who are infected, influenza viruses can be detected starting one day before symptoms begin, and for up to five to seven days after becoming sick.
—Sara Moniuszko, CBS News, 6 Feb. 2025
For those not familiar (or who maybe just have a bit of illness exhaustion!), the Centers for Disease Control (CDC) says animals infected with bird flu can shed the virus via saliva, mucus, and feces.
—Melissa Willets, Parents, 6 Feb. 2025
Most researchers believed there was a singular contact event between a bird infected with H5N1 B3.13 and a dairy cow in the Texas panhandle, in late 2023.
—Susanne Rust, Los Angeles Times, 5 Feb. 2025
See all Example Sentences for infect 
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show current usage.
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Brenda Goodman, CNN, 6 Feb. 2025
In most people who are infected, influenza viruses can be detected starting one day before symptoms begin, and for up to five to seven days after becoming sick.
—Sara Moniuszko, CBS News, 6 Feb. 2025
For those not familiar (or who maybe just have a bit of illness exhaustion!), the Centers for Disease Control (CDC) says animals infected with bird flu can shed the virus via saliva, mucus, and feces.
—Melissa Willets, Parents, 6 Feb. 2025
Most researchers believed there was a singular contact event between a bird infected with H5N1 B3.13 and a dairy cow in the Texas panhandle, in late 2023.
—Susanne Rust, Los Angeles Times, 5 Feb. 2025
See all Example Sentences for infect
Dictionary Entries Near infect
Cite this Entry
“Infect.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/infect. Accessed 11 Feb. 2025.
Copy CitationKids 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
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