boiler

noun

boil·​er ˈbȯi-lər 

1

: one that boils

2

a

: a vessel used for boiling

b

: the part of a steam generator in which water is converted into steam and which consists usually of metal shells and tubes

c

: a tank in which water is heated or hot water is stored

d

chiefly British : furnace

Examples of boiler in a Sentence

Recent Examples on the Web

Both deliver hot water thanks to an onboard water boiler fed by the 53-L fresh water tank. —New Atlas, 29 Aug. 2025

The comments were submitted on behalf of four California businesses and trade groups, including a company that uses natural gas boilers to make tomato products and a trucking association whose members are subject to EPA climate regulations. —Michael Copley, NPR, 19 Aug. 2025

The Accord’s boiler safety team began inspections in February this year, visually inspecting 51 boilers. —Mayu Saini, Sourcing Journal, 15 Aug. 2025

Goes toward energy efficient appliances such as heat pumps, water heaters and boilers, biomass stoves, home insulation, better insulated windows and doors. —Ella Nilsen, CNN Money, 14 Aug. 2025

Word History

First Known Use

circa 1540, in the meaning defined at sense 1

Phrases Containing boiler

• boiler room
• double boiler
• steam boiler

Rhymes for boiler

• broiler
• oiler
• spoiler
• toiler
• reboiler

Kids Definition

boiler

noun

boil·​er ˈbȯi-lər 

1

: a container in which something is boiled

2

: a strong metal container used in making steam

3

: a tank in which water is heated or hot water is stored