Did you know?

Click any word in a definition or example to find the entry for that word

infect - definition and synonyms

What are red words?

90% of the time, speakers of English use just 7,500 words in speech and writing. These words appear in red, and are graded with stars. One-star words are frequent, two-star words are more frequent, and three-star words are the most frequent.

Thesaurus diagram

The thesaurus of synonyms and related words is fully integrated into the dictionary. Click on the thesaurus category heading under the button in an entry to see the synonyms and related words for that meaning.

verb [transitive]     infect pronunciation in British English
Word Forms
present tense
present participleinfecting
past tenseinfected
past participleinfected
  1. 1
    [often passive] to make someone get a disease, that can be spread from one person to another

    Thousands of people have been infected.

    If you return to work too soon, you may infect other people.

    be infected with/by something:

    You can only be infected with HIV in a limited number of ways.

    1. a.
      to fill something with bacteria or other substances that spread disease
      infect something with something:

      Terrorists had threatened to infect the water supply with a deadly virus.

  2. 2
    computing if a computer virus infects a computer or computer program, it enters it and causes problems

    a virus that infects word-processing documents

  3. 3
    to make other people have the feeling or idea that you have

    She infects everyone around her with her enthusiasm.



to manipulate someone psychologically so that they begin to question their own perceptions and memories

BuzzWord Article

Open Dictionary

Dunning-Kruger effect

the phenomenon by which an incompetent person is too incompetent to understand his own incompetence

add a word


A must for anyone with an interest in the changing face of language. The Macmillan Dictionary blog explores English as it is spoken around the world today.

global English and language change from our blog
Macmillan learn live love play