the minimum amount of resources, number of customers, etc. needed to start or support a project or an activity; the minimum size that a project or activity needs to be in order to be successful
جرم بحرانی, حداقل تعداد لازم, حد بحرانی
The company needs one million customers to reach critical mass and start making a profit.
TV via internet could only be developed once a critical mass of households had broadband access.