radiator

radiator — noun

1. a heating unit, typically made of metal and attached to a wall, that warms a roo

1.nounB1
Definition

a heating unit, typically made of metal and attached to a wall, that warms a room by circulating hot water, steam, or oil through linked sections.

Example

Owen turned up the radiator because the living room was freezing.

collocation: turn up / turn down the radiator

The old classroom had cast-iron radiators that clanked loudly whenever the heating came on.

common adjective: cast-iron radiator

Common collocations
  • turn the radiator up/down/on/off
  • radiator + leak/leaking
  • bleed the radiator
  • drain the radiator
  • cast-iron radiator
  • modern radiator
  • radiator + clank/rattle/hiss
Synonyms
  • heater

    a broader term that includes electric space heaters, fan heaters, and radiators; less specific than 'radiator'

  • convector

    a type of heater that works by circulating air over heated fins rather than radiating heat; less common in everyday speech

Grammar Patterns

the radiator (in a room)

turn + radiator + up/down/on/off

Usage Note

In buildings with central heating, people often refer to 'the radiator' as a shorthand for the entire room-heating system. The verb collocations 'turn the radiator up/down/on/off' are extremely common in everyday speech.

Common Mistakes

I turned on the radiator heater.
I turned on the radiator.
'radiator' already means the heating device; adding 'heater' is redundant.

2. a device at the front of a vehicle that cools the engine by circulating liquid t

2.nounB2
Definition

a device at the front of a vehicle that cools the engine by circulating liquid through a network of thin metal tubes, releasing heat into the air passing through.

Example

Greta saw steam rising from under the hood and knew the radiator was leaking.

radiator + leak / leaking (vehicle context)

The mechanic told Felipe that the radiator needed flushing with fresh coolant.

collocation: flush the radiator

Common collocations
  • radiator + leak/leaking
  • flush the radiator
  • refill the radiator
  • radiator + overheat
  • radiator cap
  • radiator fan
  • radiator + burst
Synonyms
  • cooler

    a general term; not specific to vehicles

  • heat exchanger

    the technical engineering term; too formal for everyday use

Grammar Patterns

the radiator (of a car)

radiator + verb (leak, overheat, burst)

Usage Note

In vehicle contexts, 'radiator' always refers to the cooling device, not a heating device — exactly the opposite function from the room-heater sense. 'Coolant' or 'antifreeze' is the liquid inside, not water alone.

Common Mistakes

My car radiator is frozen, so I need to defrost it.
My car radiator has frozen, so I need to replace the antifreeze mixture.
The problem is usually the coolant freezing, not the radiator itself needing defrosting.

Word family

Synonym discussion

Sense: noun/1

A radiator is a specific type of heater that uses hot water, steam, or oil circulating through metal sections to warm a room. A 'heater' is the broadest term — it covers electric space heaters, fan heaters, oil-filled radiators, and even central heating furnaces. A 'convector' works differently: it pulls cool air over a heated element and pushes warm air out, rather than radiating heat from a metal surface. A 'boiler' is the device that heats the water, not the radiator itself — the boiler sends hot water to the radiators. For everyday situations: 'I turned on the radiator' refers specifically to a visible metal panel or column heater, while 'I turned on the heater' could mean any heating appliance.

radiator ↗heater ↗convectorboiler

Etymology

LatinEnglish

The word 'radiator' comes from the Latin verb 'radiare' (to emit rays or beams) plus the agent suffix '-or' (someone or something that does an action). It entered English in the early 1800s, first used for any device that radiates heat or light. The modern meaning of a hot-water room heater appeared in the 1840s, and the vehicle engine-cooling sense emerged later with the rise of the automobile in the early 1900s. In both senses, the core idea is the same: a device that transfers heat — either into a room (for warmth) or out of an engine (to prevent overheating).