Definition from macmillandictionary.com
We’re on a winning streak – hopefully we can keep it up.
Keep up the good work.
The trade unions continued to keep up pressure for higher wages.
She tried to appear cheerful but couldn’t keep it up.
His family kept up the pretence that he had been ill.
Try to keep up!
He had to hurry to keep up with her.
By studying hard she managed to keep up.
We always try to keep up with our competitors.
We try to keep up with what’s happening.
I told you she’s my sister, not my girlfriend. Keep up!
I found myself unable to keep up with the conversation.
It’s late. I’d better not keep you up any longer.