attrition
noun [ U ]
uk/əˈtrɪʃən/ us HR
a reduction in the number of employees in a company made by not replacing those who leave, rather than forcing people to leave their jobs:
The majority of jobs will go through natural attrition.
Staff attrition rates are high.
Compare
natural wastage
MARKETING
a reduction in the number of people who buy a product or service, for example because of its age, increased competition, etc.:
We aim to minimize the rate of customer attrition.