Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English


English definition of “mushroom”


verb [I]     /ˈmʌʃ.ruːm/ /-rʊm/
to increase very quickly : The number of computers in schools has mushroomed in recent years .Increasing and intensifying
(Definition of mushroom verb from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
Focus on the pronunciation of mushroom

Definitions of “mushroom” in other dictionaries

Word of the Day

best man

a male friend or relation of the bridegroom who stands with him and helps him during a marriage ceremony

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