From Longman Dictionary of Contemporary Englishlight up phrasal verb1 light something ↔ upLIGHT to give light to a place or to shine light on something The flames lit up the sky. The fountain is lit up at night.2 BRIGHTto become bright with light or colour At night the harbour lights up. As the screen lit up, he typed in his password.3 a) HAPPYEXCITEDif someone’s face or eyes light up, they show pleasure, excitement etc with His eyes lit up with laughter. Her face lit up with pleasure. b) light something ↔ upHAPPYEXCITED to make someone’s face or eyes show pleasure or excitement Suddenly a smile lit up her face. A mischievous gleam lit up her eyes.4 informalSMOKE to light a cigarette I watched Paul light up again. → light→ See Verb table
Examples from the Corpus
light up• She lit up another cigarette.• They're not allowed to smoke at work, so they all light up as soon as they leave.• Their garden was lit up by dozens of coloured lamps.• Fireworks lit up the night sky.light with• As he reached her side, the sky above them lit up with a vivid flash of lightning.• The boy's face lit up with delight.• And when Cosby finally opens wide and swallows, you watch him light up with delight.• The dark wood was now lit up with lurid flashes of artillery and the firefly sparkle of rifles....• Only when she mentions the name Miranda do their eyes light up with respect.• However, the London skyline was lit up with the huge warehouse fire.• His eyes lit up with the thought.• I lit up with trembling fingers.• In the 50s a tennis player lit up with warmth the whole world. 