to add to something to make it better or more interesting She decided to wear her large silver pin to help freshen up the black dress.I'm getting another drink - can I freshen yours up?
1. To clean oneself, rearrange one's clothing, or reapply makeup: I went upstairs to freshen up quickly before we left for the party.
2. To rearrange or renew something in order to make it more attractive or comfortable: Putting new pillows on the couch really freshened the room up. I freshened up the apartment by making new curtains.