critical mass is a noun meaning "the minimum amount (of something) required to start or maintain a venture". It carries 2 recorded senses.
the minimum amount (of something) required to start or maintain a venture
“the battle for the computer market has now reached critical mass”
“there is now a critical mass of successful women to take the lead”
“they sold the business because it lacked critical mass”
the minimum mass of fissionable material that can sustain a chain reaction
Definitions, synonyms and semantic relations for critical mass come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.