cushion
US /ˈkʊʃ.ən/
UK /ˈkʊʃ.ən/

1.
2.
something that protects against impact or provides a soft landing
:
•
The air bags provide a safety cushion in a car crash.
•
The thick carpet acts as a sound cushion.
3.
a sum of money kept in reserve
:
•
They have a financial cushion to fall back on.
•
The company built up a cash cushion during the good years.