immersion heater

noun

1. a small electric coil used to heat a liquid, as a cup of water, in which it is immersed.

immersion heater

noun

1. an electrical device, usually thermostatically controlled, for heating the liquid in which it is immersed, esp as a fixture in a domestic hot-water tank

Word History and Origins

Origin of immersion heater¹

First recorded in 1910–15