1. cheer up - Verb
2. cheer up - Interjection
become cheerful
cause (somebody) to feel happier or more cheerful
Source: WordNetThe best way to cheer yourself is to cheer up somebody else. Mark Twain
I always cheer up immensely if an attack is particularly wounding because I think, well, if they attack one personally, it means they have not a single political argument left. Margaret Thatcher
Why don't they just accept that life is sad and cheer up it's not forever. Jeremy Hardy
Bring you down, can't bring you down Bring you down, can't hear the sound Run through the river and head to town Pretty little moon with it's head hung down Chin up. Cheer up. Ryan Adams
Cheer up everyone," he said, a new brightness to his voice. "Since we're all going to die horribly anyway, what's there to be worried about? Derek Landy
Whenever I'm sad, I just put on 'SpongeBob' and I cheer up. Richard Harmon