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

Two of the buildings kept their conventional boiler setup, while the third had the new heat pump and FCU system installed. — Christopher McFadden, Interesting Engineering, 17 Oct. 2026

In 2026, Octopus released the Cosy 12, its most powerful smart heat pump system to date, which runs on electricity and is designed specifically to warm large, older homes up to four times more efficiently than a gas boiler, according to the company. — Derek Rose, Time, 15 Oct. 2026

Heating oil is primarily used to power furnaces, boilers and water heaters in residential or commercial heating systems. — ABC News, 14 Oct. 2026

One is to use more of the heat, such as preheating water for the buildings’ boilers or melting snow. — Moones Alamooti, The Conversation, 9 Oct. 2026

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