A large open-headed cask, usually set up on end in an out-house or close to a dwelling, serving as a reservoir for rain- or pipe-water.(noun)
A water-beetle, as Dytiscus marginatns and related species.(noun)
The Century Dictionary (Public Domain)
Use "water-butt" in a sentence
"From the moment he enters and wakes up by doing a handstand in a water-butt and mixes a Prairie Oyster by putting the glass in his trousers and shaking his hips, Mark Rylance gives a historic performance as "Rooster" Byron, who is Lord of Misrule, Puck, Robin Hood and Socrates all rolled up in a single, unforgettable character."
"It was once the main residence at Leatherarse Gully, another bungalow with a low tin roof and veranda, with a water-butt at one corner."
"A little while afterwards he had taken a new house, and was going headlong to ruin for want of a water-butt."