[v] make lighter or brighter; "This lamp lightens the room a bit"
[v] begin to smoke; "After the meal, some of the diners lit up"
[v] start to burn with a bright flame; "The coal in the BBQ grill finally lit up"
[v] ignite; "The sky lit up quickly above the raging volcano"
[v] become clear; "The sky cleared after the storm"