put someone's mind at rest
US /pʊt ˈsʌm.wʌnz maɪnd æt rɛst/
UK /pʊt ˈsʌm.wʌnz maɪnd æt rɛst/

1.
使某人放心, 消除某人的顾虑
to tell someone something that makes them stop worrying
:
•
I called her to put her mind at rest about the children.
我打电话给她,让她放心孩子们的安全。
•
The doctor's explanation helped to put my mind at rest.
医生的解释帮助我放下了心。