settle down
US /ˈset̬.l̩ daʊn/
UK /ˈset̬.l̩ daʊn/

1.
to become calm, quiet, or comfortable
:
•
The children finally settled down after playing all afternoon.
•
Please settle down and listen to the instructions.
2.
to start living a quiet and routine life in one place, often by marrying and having children
:
•
After years of traveling, he decided to settle down and buy a house.
•
They got married and settled down in the suburbs.