Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “mushroom”


verb [I]
/ˈmʌʃruːm/ informal
to increase in number or develop very quickly: Low-cost airlines have mushroomed in recent years.mushroom into sth The walkout mushroomed into a large-scale battle.mushroom from sth to sth Area budgets mushroomed from $3.7 billion in 2005 to more than $6.3 billion this fiscal year.
(Definition of mushroom from the Cambridge Business English Dictionary © Cambridge University Press)
What is the pronunciation of mushroom?
Add Cambridge dictionaries to your browser to your website

Definitions of “mushroom” in other dictionaries

Word of the Day


a small company that makes beer, usually using traditional methods, and often has a restaurant where its beer is served

Word of the Day


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