lighten up Meaning, Definition & Usage

1. verb make more cheerful
   lighten; buoy up.
   
   • the conversation lightened me up a bit
2. verb become more cheerful
   lighten; buoy up.
   
   • after a glass of wine, he lightened up a bit
3. verb make lighter or brighter
   lighten; brighten.
   
   • The paint will brighten the room
4. verb become lighter
   lighten.
   
   • The room lightened up

WordNet