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

Heat pumps, which use electricity to generate heat via refrigerants—like an air conditioner working in reverse—offer a highly efficient solution, producing heat at twice or more the efficiency of electric boilers. —Angela Velasquez, Sourcing Journal, 11 Nov. 2025

In a phone call last spring, Kashunamiut School District Superintendent Jeanne Campbell described a host of problems related to the Chevak school's boiler and broken water pipes that impacted the fire sprinkler system. —Emily Schwing, NPR, 10 Nov. 2025

Stationary engineer and boiler operator These workers maintain heating, air conditioning and power systems in big buildings and plants. —Daniel De Visé, USA Today, 9 Nov. 2025

The tests were conducted under various loads and combustion conditions, allowing for an assessment of the impact of flame position on the boiler’s thermal performance and heating surface operation. —Prabhat Ranjan Mishra, Interesting Engineering, 30 Oct. 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