smooth over
US /smuːð ˈoʊvər/
UK /smuːð ˈoʊvər/

1.
сгладить, замять
to make a problem or difficulty seem less serious or important than it really is
:
•
He tried to smooth over the argument between his friends.
Он пытался сгладить ссору между своими друзьями.
•
The manager tried to smooth over the customer's complaints with a discount.
Менеджер попытался сгладить жалобы клиента скидкой.