The antonyms for the phrase "setting alight" would be to extinguish, put out, or douse. When we talk about setting something alight, we are referring to igniting or lighting something on fire - this could be a matchstick, a candle, a firework, or any object that can be set ablaze. However, the opposite of this action would be to put out the fire, preventing it from spreading further. Firefighters use special equipment and techniques to extinguish fires, which can save lives and prevent property damage. Overall, the antonyms for "setting alight" are related to extinguishing and controlling fires, which are crucial for safety and wellbeing.