light up
phrasal verbDefinition of light up
1
of a light
: to become lit : to begin shining
All of the lights on the display suddenly lit up.
—often used figuratively to express interest or pleasure His eyes/face lit up when she walked in the room.
2
informal, of a telephone
: to show a light indicating that someone is calling
When the DJ announced a contest, the phones lit up.
3
informal
: to light a cigarette
I can't wait to light up after work.