peace ****
peacefulness
peace of mind
repose
serenity
heartsease
ataraxis

More than his own peace of mind was also involved here.

Rather more than was good for her peace of mind.

The public has a right to its peace of mind.

He'd been thinking about her a little too often for his own peace of mind.

Far better to pay for peace of mind and take out cover before you go.

But he would go back with some peace of mind.

I've got to know for my own peace of mind.

Where do we go to find our peace of mind?

He was much too close for her peace of mind now.

I don't need a test to give me peace of mind.