cheer up

cheer up  {v.}

1. To feel happy; stop being sad or discouraged; become hopeful, joyous, or glad.

Jones was sad at losing the business, but he cheered up at the sight of his daughter.

Cheer up! The worst is over.

2. To make cheerful or happy.

The support of the students cheered up the losing team and they played harder and won.

We went to the hospital to cheer up a sick friend.