critical mass
noun
Simple meaning
The minimum mass of fissionable material that can sustain a chain reaction.
Pronunciation
Say it like this:
kritihkuhlmasSay the bold part a little louder.
IPA pronunciation (US)
ˈkɹɪtɪkəlmæs
This word is pronounced essentially the same in American and British English, so one transcription covers both.
IPA (International Phonetic Alphabet) is a standard way of writing speech sounds.
Definition
Everyday modern meanings first, grouped by part of speech.
noun
nuclear physics
The minimum mass of fissionable material that can sustain a chain reaction
nuclear physics
The minimum amount of fissile material needed to support a self-sustaining nuclear chain reaction.
The minimum amount (of something) required to start or maintain a venture
by extensionfigurative
The minimum amount of something or the minimum number of people needed to trigger a phenomenon.
A direct action event in which bicycle riders travel through city streets as a group.
Word Aura™
How this word commonly comes across.
Aura for this meaning
This meaning: The minimum mass of fissionable material that can sustain a chain reaction
Used this way, critical mass is a specialist word that usually carries little praise or criticism of its own. This is a scientific use: it names something precisely within a field of study, so it appears in research and teaching more than in conversation.
- Emotional tone
- Neutral
- Formality
- Specialist/technical
- Intensity
- Not strongly marked
- How common
- Specialized
- Connotation
- Clinical and technical
- Usage feel
- Technical and specialized
Where it naturally appears
- Science
- Academic writing
- Technical/specialist writing
Usage note
In general conversation this sense usually needs explaining — outside its field, people reach for a plainer word.
Word Aura describes common impressions, not a measurement. Tone changes with sentence, speaker, relationship and situation.
Share your sentence
Ask Vocabaura
Understand the word your way.
What Does It Mean Here?
Words can change meaning depending on context.
Use it yourself
Knowing “critical mass” starts when you use it. Pick a next step, all free.
Dictionary data from Wiktionary via the Free Dictionary API. Simple meanings, combinations and word intelligence are built from verified reference data, no AI is used to load this page.