- verb to extinguish a flame or a light
- verb to cool a metal rapidly by placing it in liquid, in order to make it harder or softer depending on the metal
- To extinguish or end abruptly. For example, to extinguish an electric arc.
- To suppress, or reduce the degree of something. For instance, to suppress oscillation, or reduce the level of phosphorescence of a material.
- To cool abruptly. For example, to treat a metal by heating it and immersing it in a cold liquid.