Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “virus”

virus

noun [C]  /ˈvɑɪ·rəs/ us  

virus noun [C] (SMALL ORGANISM)

biology a very small organism that causes disease in humans, animals, and plants A virus is also a disease caused by a virus: She’s had a virus for several days.

virus noun [C] (COMPUTER PROBLEM)

a hidden set of instructions in a computer program that is intended to introduce faults into a computer system or cause it to perform actions that were not planned
(Definition of virus from the Cambridge Academic Content Dictionary © Cambridge University Press)
What is the pronunciation of virus?
Add Cambridge dictionaries to your browser to your website

Definitions of “virus” in other dictionaries

Word of the Day

give the green light to sth

to give permission for someone to do something or for something to happen

Word of the Day

Highly delighted, bitterly disappointed, ridiculously cheap: adverbs for emphasis.

by Liz Walter,
October 22, 2014
We often make adjectives stronger by putting an adverb in front of them. The most common ones are very and, for a stronger meaning, extremely: He was very pleased. The ship is extremely large. However, we don’t use very or extremely for adjectives that already have a strong meaning, for example fantastic,

Read More 

life tracking noun

October 20, 2014
the use of one or more devices or apps to monitor health, exercise, how time is spent, etc.

Read More