Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “critical mass”

See all translations

critical mass

noun [C usually singular or U] uk   us  
specialized physics the smallest amount of matter that is needed to produce a nuclear chain reaction the size that something needs to reach before a particular change, event, or development can happen
(Definition of critical mass from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of critical mass?
Add Cambridge dictionaries to your browser to your website

Definitions of “critical mass” in other dictionaries

Word of the Day

derivative

If something is derivative, it is not the result of new ideas, but has been developed from or copies something else.

Word of the Day

Euphemisms (Words used to Avoid Offending People)

by Kate Woodford,
March 04, 2015
​​​ We recently looked at the language that we use to describe lies and lying. One area of lying that we considered was ‘being slightly dishonest, or not speaking the complete truth’. One reason for not speaking the complete truth is to avoid saying something that might upset or offend people. Words and

Read More 

snapchat verb

March 02, 2015
to send someone a message using the photomessaging application Snapchat We used to have a thing until he got a girlfriend. now

Read More