Meaning & use
infect
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Meanings
verbtransitivemedicalbiology
To cause a person, animal, or plant to carry a disease-causing organism, often by contact or through the environment.
Grammar: Takes an object and is often followed by with: infect someone with a virus.
Patterns
- infect someone with something
- be infected by something
- infect a wound
A stray dog bit him and infected the cut with bacteria.
Standing water can infect nearby plants with fungal disease.
She was infected by a virus after caring for her sick cousin.
verbtransitivefigurative
To spread an emotion, attitude, or way of behaving quickly through a group.
Grammar: Also takes an object, but the object is usually a feeling or quality: infect the room with laughter.
Patterns
- infect someone with enthusiasm
- infect a group with fear
- infect the atmosphere
His confidence infected the whole sales team before the launch.
Panic infected the crowd after the lights suddenly went out.
One upbeat playlist infected the waiting room with calm.
Word forms
| third person singular | infects |
|---|---|
| past tense | infected |
| past participle | infected |
| -ing form | infecting |
Common combinations
- infect someone with something
- Mosquitoes can infect people with malaria.
- become infected
- The scrape became infected after the camping trip.
- infect a computer
- A suspicious download infected the office computer.
- infect the mood
- One gloomy remark can infect the mood of a meeting.
Synonyms and how they differ
- contaminate
- Contaminate is broader and often means making food, water, or material impure; infect specifically involves disease agents or, figuratively, feelings.
- spread
- Spread simply means distribute widely; infect suggests transmission into a person, system, or group.
- corrupt
- Corrupt implies damaging morals, data, or judgment, not biological disease.
Opposites
Word family
- infection noun
- The process of infecting or a disease caused by an organism.
- infectious adjective
- Able to spread disease, or used figuratively for quickly spreading laughter or enthusiasm.
- infected adjective
- Carrying disease or contamination.
Commonly confused: infect or infest? infect or affect?
infect vs infest
Infest means to overrun a place with pests in large numbers; infect means to transmit disease into a person, animal, plant, or system.
infect vs affect
Affect is the usual verb meaning influence; infect is narrower and suggests transmission of illness or feeling.
Practice
Which sentence uses infect correctly for the medical sense?
Choose one answer.
A tick transmitting Lyme disease fits the biological pattern infect someone with something. Ants overrun a place, so infest fits better; a cleaned cut may become infected rather than infect again; a voice is not made ill by volume.
Make it your own
Write a sentence using “infect”, then check it and compare it with the examples above.