Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

  

English definition of “infectious”

infectious

adjective     /ɪnˈfekʃəs/
DISEASE An infectious disease can be passed from one person to another.Bacteria, moulds, germs and virusesPassing on illness and causing diseaseDisease and illness - general words
LAUGH Infectious laughter or feelings quickly spread from one person to another: infectious enthusiasm Humour and humorous
(Definition of infectious adjective from the Cambridge Learner's Dictionary © Cambridge University Press)

Definitions of “infectious” in other dictionaries

Word of the Day

warm-up

something that you do to prepare yourself for an activity, especially gentle exercises before a physical activity

Word of the Day

Blog

Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More