{f} throw water on, plunge into water; strike, punch, hit; take in or lower a sail (Nautical); extinguish a fire or flame with water; become completely wet; take off a hat; remove any item of clothing (Archaic)
If you douse someone or something with a liquid, you throw a lot of that liquid over them. They hurled abuse at their victim as they doused him with petrol. Variant of dowse