- Physics. the amount of a given fissionable material necessary to sustain a chain reaction at a constant rate.
- an amount necessary or sufficient to have a significant effect or to achieve a result: a critical mass of popular support.
Origin of critical mass
First recorded in 1940–45
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- the minimum mass of fissionable material that can sustain a nuclear chain reaction
- the minimum amount of money or number of people required to start or sustain an operation, business, process, etcthe critical mass for a subscription digital sports channel
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The term critical mass is used to refer generally to the minimum amount of something needed to produce a given effect: “The town needs a critical mass of industry to attract more business.”
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.