continuing education
noun /kənˌtɪnjuːɪŋ edʒuˈkeɪʃn/
  /kənˌtɪnjuːɪŋ edʒuˈkeɪʃn/
 (also adult education)
 [uncountable]- education for adults that is available outside the formal education system, for example at evening classes or over the internet
- We have a thriving continuing education department.