A pistol-shaped object, ostensibly for kids, designed to project water or other liquids at an opponent. Due to the wonders of modern technology it is now possible to obtain water-shooting rifles, machine guns, hand grenades and all kinds of exotic weaponry.

Tip: for a wonderful way to spend a sunday afternoon, acquire a group of friends and equip them all with water-weaponry. Poke your head out the window to ensure that it's sunny outside. Take a big bucket to the nearest pub and get it filled with water. Now all retire outside with a pint of lager in one hand and the weapon of your choice in the other. Start shooting. Repeat until:

(a) The landlord/police/other authority figure yells "Go on, piss off the lot of you"
(b) One or more members of your group are too drunk to continue the battle
(c) Night falls and it gets too cold to carry on