noun

• A person who boils something.
• A steam boiler.
• An apparatus for heating circulating water or other heat transferring liquid.
• A device consisting of a heat source and a tank for storing hot water, typically for space heating, domestic hot water etc., disregarding the source of heat.
• A kitchen vessel for steaming, boiling or heating food.
• A sunken reef, especially a coral reef, on which the sea breaks heavily.
• A tough old chicken only suitable for cooking by boiling.
• (UK, Australia, slang, derogatory) An old woman.
• (rare, informal) Boilerplate.
• Short for Brompton boiler. [(UK, slang, obsolete, historical, mostly plural) Any of the buildings comprising the Kensington Museum and School of Art.]