Definition of "light up" []

• To bring light to something, to brighten. (verb)
• To become light, to brighten. (verb)
• To light a cigarette, pipe, etc. (verb)
• To make happy. (verb)
• To open fire on a target or group of targets. (verb)

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• "The flow cytometer uses a laser to light up cells if the cells express certain markers that should not, in normal circumstances, be present on the T cells."
• "He played the light up the wall to the fifty-foot-high ceiling and then followed the wall away from him until the surface ended at a right angle to another wall."
• "We light up and lean back, feeling relaxed and hedonistic now, lazily poking into our plates as though our parents forced us to eat Napoleons every day for breakfast, lunch, and dinner."