infection

infection — noun

1. a state in which harmful germs, bacteria, or viruses get into your body and star

1.nounB2
Definition

a state in which harmful germs, bacteria, or viruses get into your body and start to multiply, which can make you feel unwell or cause a disease.

Example

Joaquín stayed home from school after the doctor said his ear infection needed rest and medicine.

ear / throat / wound infection

The nurse told Meera to keep the cut clean so that no infection would appear.

Common collocations
  • ear infection
  • throat infection
  • wound infection
  • bacterial infection
  • viral infection
  • chest infection
  • fight an infection
  • treat an infection
  • spread an infection
  • infection rate
  • risk of infection
  • signs of infection
Synonyms
  • disease

    broader term; not all diseases come from germs (e.g. heart disease)

  • illness

    general feeling of being unwell; may or may not be from an infection

  • contagion

    formal or technical; focuses on the way a disease passes from person to person

Antonyms
  • immunity

    the body's ability to resist or fight off infection

Grammar Patterns

an infection (countable)

infection (uncountable)

Usage Note

Countable when referring to a specific instance in a part of the body ('an ear infection', 'a wound infection'). Uncountable when speaking generally about the condition ('the risk of infection', 'infection can spread').

Common Mistakes

He got infection.
He got an infection.
when referring to a specific illness episode, use the article 'an'.
The infection spreaded quickly.
The infection spread quickly.
'spread' has the same form in past tense.

2. the situation in which harmful software such as a virus or other malware invades

2.nounB2
Definition

the situation in which harmful software such as a virus or other malware invades a computer system, network, or file, causing damage, stealing data, or disrupting the normal way the system works.

Example

Once the virus reached the company server, the infection wiped out thousands of important files.

the infection + destructive effect

Jisoo installed security software to protect her laptop from any malware infection.

malware infection

Common collocations
  • computer infection
  • malware infection
  • virus infection
  • system infection
  • network infection
  • detect an infection
  • remove an infection
  • prevent infection
Synonyms
  • virus

    more specific; a type of malware that spreads by copying itself

  • malware

    general term for any harmful software, including viruses, worms, and spyware

Grammar Patterns

an infection (countable, a specific attack)

infection (uncountable, the general phenomenon)

Usage Note

Distinguish from sense 1 by context: this sense uses nouns such as 'virus', 'malware', 'computer', 'software', 'network', 'data'. Common in technology news and IT workplace language.

Common Mistakes

My phone caught an infection from a website.
My phone got infected by malware from a website.
'infection' for computers is more formal or technical; everyday speech often uses 'virus' or 'malware' directly.

3. the process by which a feeling, mood, or attitude spreads from one person to oth

3.nounC1
Definition

the process by which a feeling, mood, or attitude spreads from one person to others in a group, so that everyone begins to feel or act in a similar way, as if the emotion were a disease moving through people.

Example

A strange nervous infection seemed to pass through the crowd as they waited for the exam results to be announced.

The speaker's excitement was an infection that soon had the whole audience cheering and laughing together.

the infection of [emotion]

Common collocations
  • infection of fear
  • infection of joy
  • infection of excitement
  • infection of panic
  • quiet infection
  • slow infection
Synonyms
  • contagion

    near synonym; 'emotional contagion' is a formal term used in psychology

  • spread

    neutral and general; lacks the implied force of 'infection'

  • transmission

    more technical; often used for ideas or cultural traits

Grammar Patterns

the infection of + emotion/attitude

Usage Note

Almost always followed by 'of' plus an emotion or attitude. The emotion can be positive ('the infection of joy') or negative ('the infection of fear'). This sense is found more in written, literary, or formal contexts than in everyday conversation.

Common Mistakes

Her laugh was infectious, and soon everyone got the infection.
Her laugh was infectious, and soon everyone was laughing too.
'infection' in the emotional sense is less common in everyday English; use 'infectious' (adjective) instead for natural-sounding speech.

4. the act or process of damaging someone's moral character or sense of right and w

4.nounC2
Definition

the act or process of damaging someone's moral character or sense of right and wrong, as if a bad influence were slowly poisoning their values and principles.

Example

The old storyteller warned young Ilan to stay away from the gambling halls, calling them an infection of the spirit.

an infection of the spirit / soul / mind

Many parents feared that certain violent shows would become an infection of their children's values.

an infection of [values / character]

Common collocations
  • infection of greed
  • infection of the soul
  • infection of the spirit
  • moral infection
  • spiritual infection
Synonyms
  • corruption

    more common and direct; 'moral corruption' is standard in most contexts

  • contamination

    suggests a pure thing becoming impure; less common for morals than for physical things

  • degradation

    suggests a lowering of quality or status over time

Antonyms
  • purity

    moral cleanliness or integrity

Grammar Patterns

an infection of + moral quality

the infection of + [society/mind/soul]

Usage Note

Always metaphorical; do not use for literal physical contamination. Typically appears with 'a' or 'the' followed by 'of' plus an abstract noun describing the corrupted quality. Found almost exclusively in literary, religious, or philosophical writing.

Common Mistakes

He suffered from a moral infection.
His morals were infected by greed.
the noun 'infection' for moral corruption is rare and literary; the verb 'infect' or adjective 'infected' sound more natural in most contexts.

Word family

Synonym discussion

Sense: noun/1

These five words are often confused by learners because they all relate to being unwell, but each has a different scope. 'Infection' refers specifically to the state in which germs (bacteria, viruses, fungi) have entered the body and are active — not every disease is an infection (diabetes is a disease, not an infection). 'Disease' is the broadest term and covers any condition that stops the body from working normally, whether caused by germs, genetics, or ageing. 'Illness' focuses on how you feel — the subjective experience of being unwell; you can have a disease without feeling ill if it is managed well. 'Virus' is a specific type of germ, not a state. 'Contagion' is a more formal or historical term that emphasises how a disease passes between people. In daily use: you go to the doctor for an 'infection' and get antibiotics; you manage a 'disease' long-term; you take a day off work for an 'illness'. The most practical pair to distinguish is infection vs. disease: all infections are diseases, but not all diseases are infections.

infection ↗disease ↗illness ↗virus ↗contagion

Common collocations

Nouns

  • source of infection
  • risk of infection
  • site of infection
  • signs of infection
  • infection control

Adverbs

  • quickly spread
  • easily transmitted
  • rapidly spreading
  • highly infectious

Phrases

  • risk of infection
  • spread of infection
  • source of infection
  • signs of infection
  • infection prevention

Prepositions

  • infection from
  • infection in
  • infection through
  • infection among

Etymology

LatinMedieval LatinMiddle EnglishModern English

'Infection' entered English in the late 14th century from the Latin word 'infectio', meaning 'a dipping in, staining, or dyeing'. The root is the verb 'inficere' — a combination of 'in' (in, into) and 'facere' (to make, to put). In Latin, 'inficere' first meant 'to dip into' something like dye, but it quickly took on a darker meaning: 'to stain, taint, or spoil'. By Medieval Latin, the word was used for the idea of a disease entering and 'staining' the body, a metaphor that stuck. English first used 'infection' for literal disease in the 1500s, and the figurative uses for emotional and moral 'tainting' developed in the 1600s. The computing sense is modern, from the 1970s and 1980s, borrowing the same metaphor of contamination.