light up

verbs

start to burn with a bright flame
"The coal in the BBQ grill finally lit up"
light up
is a type of (narrower)
start to burn or burst into flames
"Marsh gases ignited suddenly"; "The oily rags combusted spontaneously"
catch fire, combust, conflagrate, erupt, ignite, take fire
make lighter or brighter
"This lamp lightens the room a bit"
illume, illuminate, illumine, light, light up
become clear
"The sky cleared after the storm"
brighten, clear, clear up, light up
ignite
"The sky lit up quickly above the raging volcano"
light up
is a type of (narrower)
cause to start burning; subject to fire or great heat
"Great heat can ignite almost any dry matter"; "Light a cigarette"
ignite, light
begin to smoke
"After the meal, some of the diners lit up"
fire up, light, light up