Light up

What is Light up ?

Light up is (verb) 1. to make something bright The flames from the burning petrol store lit up the night sky. The firework display lit up the gardens and the lake. 2. to become bright and happy Her face lit up when she saw the presents under the Christmas tree. 3. to start to smoke Please do not light up until coffee has been served.

 

source: Easier English, Student Dictionary Upper Intermediate Level