A vessel of sheet-metal in which clothes to be washed are boiled.(noun)
The Century Dictionary (Public Domain)
Use "wash-boiler" in a sentence
"She went out to the wash-house in the little shed at the back of the garden to fire up the wash-boiler out there, a huge kettle built right into a kind of oven, pump it full of cold water, and add the soap."
"Three minutes later, dressed in my outer clothes and dripping like a blanket that's just been hauled from a wash-boiler, I was on my way up the enclosed gangway to the well-deck of the oil-rig a hundred feet above my head."
"From the appearance of the wash-boiler, running over with dried apples that were being boiled without care, I judged every thing to be done after the same style."