Snuff means to put out a flame, like when you pinch out a candle with your fingers or use a special cone-shaped tool called a snuffer to cover the flame and make it go out. Before electric lights were invented, people relied on candles and oil lamps for light, so snuffing them out carefully was an important daily task. People would snuff out candles before bed to prevent fires, and servants in grand houses would walk through rooms each night, snuffing candles one by one.

When you snuffed a candle properly, it would go out cleanly without smoking up the room.

People also use snuff out as a metaphor for ending something completely, like when a drought snuffs out a farmer's hopes for a good harvest, or when a new rule snuffs out students' plans for a field trip.